Osa EXPOSED: .osa Files, +README-WARNING+.txt, and teamblding@outlook.com

You open Documents the way you did yesterday. The first photo should still be 1.jpg. The second shot should still be 2.png. The invoice should still be invoice-2026.pdf. The tax sheet should still be taxes.xlsx. Instead every familiar name has an ID, an inbox, and a second ending tacked on. 1.jpg is now 1.jpg.[2AF20FA3].[teamblding@outlook.com].osa. 2.png is now 2.png.[2AF20FA3].[teamblding@outlook.com].osa. A small text file named +README-WARNING+.txt is sitting in the same folder, as if it has always belonged there. The desktop wallpaper may already look wrong.

That is the trap, not a glitch.

This page is for the hour those names appear. It is not a miracle key. It is a map of the trap, so the note does not become your incident plan.

Overview

Osa ransomware locks the files first. Then it keeps the old name and the old type, hangs a victim ID in brackets, hangs the inbox teamblding@outlook.com in brackets, and appends .osa. Then it drops +README-WARNING+.txt, swaps the desktop wallpaper, and talks like a recovery desk. The note is a storefront. It shouts that files are Encrypted and Stolen. It tells you the only way back is to contact them and pay for decrypt. It points you at that one Outlook address, misspelling and all. There is no printed $ ransom. This page will not invent a wallet, a Session ID, an onion, or a victim $ figure to finish a sentence the note never printed.

If you are staring at a pile of .osa files and that text note, you are in a ransom incident, not a broken disk and not a Windows pop-up. The folder is the evidence. The note is a checkout. Stay with the folder, not with the script.

The first tell is the rename. In the sample used for this page, 1.jpg becomes 1.jpg.[2AF20FA3].[teamblding@outlook.com].osa. 2.png becomes 2.png.[2AF20FA3].[teamblding@outlook.com].osa. invoice-2026.pdf becomes invoice-2026.pdf.[2AF20FA3].[teamblding@outlook.com].osa. taxes.xlsx becomes taxes.xlsx.[2AF20FA3].[teamblding@outlook.com].osa. family.mp4 becomes family.mp4.[2AF20FA3].[teamblding@outlook.com].osa. You can still read what the file used to be. You cannot open it. Windows may call the type an OSA File and offer a useless “choose an app” box. An app cannot talk locked bytes back into a JPEG.

The second tell is the note. After the files are locked, the malware drops +README-WARNING+.txt into the same folders and changes the wallpaper so the whole screen is a billboard. README sounds like a guide. WARNING sounds like a siren. The plus signs on both ends look like tape around a crime scene. Put them together and the first English you can still read after the photos break is a sales flyer. The flyer is meant to be opened. It is not meant to be trusted.

Osa sits in the Makop family of lockers, the same tree scanners also tag as Phobos. The brand on the file ending can change. The sales floor stays familiar: a readable name, a hex-looking ID, an inbox baked into the filename, a text note, a wallpaper, a stolen-data shout, and a mail aisle. A different word on the extension does not make a new rescue. It is still the same kind of shop with a new sign in the window.

Name the locker. Osa here is malware. It is not a real OSA organization, not an optical society, not a hospital system, not a school, not a vendor on a letterhead. If someone forwards this page as proof a living OSA org was “exposed,” they are mixing a locker nickname with a company that already used those three letters. The files ending in .osa are the problem. The organizations are not.

That is the whole pitch. A locked folder of names ending in .osa, with 2AF20FA3 and teamblding@outlook.com sitting in the middle of each one. A +README-WARNING+.txt file that talks like a recovery brief. A wallpaper that repeats the same squeeze. A stolen-data claim with no numeric clock. A 100% refund promise that is not a contract. There is no public free decryptor known for this strain. There is no reason to mail that inbox today because a text file told you to.

The .osa name plus the ID and inbox is the first warning

Most lockers pick an extension so you notice the change in seconds. This one uses .osa and also stamps [2AF20FA3] and [teamblding@outlook.com] into the filename. The extra cruelty is how readable the listing stays. You do not have to decode anything. You can still see 1.jpg inside 1.jpg.[2AF20FA3].[teamblding@outlook.com].osa. You can still see the invoice year. You can still see the word taxes. The familiar words are still in the folder. The files are not familiar anymore.

Do not treat that readable name as a fix. Do not strip .osa off the end and expect Photos or Excel to open the file. Do not delete the bracketed ID because it looks ugly. Do not delete the bracketed inbox because the spelling looks wrong. Do not run a bulk “extension fixer” you found in an ad. The name is a label. The lock is in the content. Editing the label can make a later trusted tool have a harder time matching the file to what it was. Leave the locked copies as they are until you have a clean machine and a plan that does not start in a criminal inbox.

The extra ending also does advertising. Anyone who sees vacation.jpg.[2AF20FA3].[teamblding@outlook.com].osa next to +README-WARNING+.txt can pretend they already have your case. A later fake helper will quote the extension, the ID, and the Outlook tag back to you as if that were expertise. Those strings are public. They are sitting in the folder. Quoting them proves nothing except that they can read a listing.

+README-WARNING+.txt is a sales floor, not a help file

The ransom note is a plain text file with a name that sounds like documentation wrapped in caution tape. +README-WARNING+.txt wants the first click after the panic. Plenty of real software drops a README. This one uses that habit against you. It is meant to be the first English you can still read when the photos will not open. The plus signs are costume. They look like a sealed envelope. They are not a seal you can redeem.

Double-clicking it opens Notepad. That is why a panicked first click feels like opening the help page. It is not help. It is the demand, written so it looks official enough to follow. The filename is built to look like paperwork. README. WARNING. A .txt ending Windows already trusts. Paperwork is easier to obey than a threat.

Keep the file on disk. Then close it. Do not treat it as a set of steps you should follow. Do not tidy the filename. Do not drop the plus signs so it “looks cleaner” in a screenshot. Copy +README-WARNING+.txt the way you would copy a serial off a stolen laptop. That string is how a responder matches this locker. It is not a coupon you redeem by mailing teamblding@outlook.com.

Files are Encrypted and Stolen is a shout, not a lab report

The sample opens under a header that reads Attention and What’s happened. Then it shouts Files are Encrypted and Stolen. That pair is the second squeeze. Locking the photos is one threat. Claiming a stolen copy already sits somewhere else is another. You are supposed to feel that even a backup will not save you, because the other side already has a duplicate they can leak. The flyer never names a leak site. It never names a clock. It just says Stolen so the rest of the page feels like the only adult in the room.

The shout is also a brand. Later search ads will quote it. Later “helpers” will paste Encrypted and Stolen so they sound close to your folder. Anyone can copy a headline. Copying Files are Encrypted and Stolen does not mean they can reverse .osa. It means they read the same note you did, or they read a screenshot of it.

If the shout is sitting in more than one folder, that is normal for this family. Lockers drop the same text in many places so you cannot miss it. Finding five copies is not five incidents. It is one incident with a loud flyer. Keep one clean copy as evidence. You do not need to open every copy. You do not need to compare them in mail to teamblding@outlook.com.

teamblding@outlook.com is checkout, not support

The printed contact is teamblding@outlook.com. Copy that string exactly. The missing “u” is not a typo you should fix before you write it down. It is the mark. A later fake helper will “correct” it to teambuilding and then sell you a different inbox. Do not help them. The sample used for this page prints teamblding@outlook.com, and that is the aisle.

A private inbox puts you in a room they own, on an account they can delete, with a thread they can screenshot and reuse. Email would feel like a ticket. This email is not a ticket. It is how a locked photo becomes a negotiation. The note says contact us by email and you will receive instructions for decrypting all files. Instructions is a soft word for a price. Decrypt is a soft word for pay.

Do not open a fresh mail account because the note said to. Do not send a test file to prove you are a real victim. Do not paste a folder listing into a new message. Do not argue about money as if a discount were available. Those addresses belong to the people who locked the files. Writing them is the product. A $0 first message is still checkout. It still tells them this victim answers.

Strong encryption is a costume, not a key in your hand

Under Recommendation, the note says we use strong encryption, nobody can restore your files except us. That sentence is meant to shut down argument. It sounds like a standard. It sounds like a lab. It sounds like something you cannot argue with at the kitchen table. It is still attacker copy. Naming “strong encryption” is not the same as handing you a proof. It is also not a reason to start mailing keys into an inbox they own.

What the note is actually selling is helplessness. If the lock is “impossible” without their key, then their mail is the only aisle. If nobody else can restore the files, then paying for decrypt starts to feel like the last remaining lever. The flyer does not name a cipher. It does not print a wallet. It just says strong, then points at teamblding@outlook.com. That is a sales paragraph, not a lab report.

People hear strong encryption and go looking for a matching “osa decryptor” in ads. That search is the next trap. A tool that promises to reverse .osa because a ransom note printed the word strong is selling the same fear in a different window. Leave the locked files alone. Do not feed them to a mystery app that asked for admin rights because a text file named a lock.

100% refund of all files is a costume, not a contract

Under Solution and What guarantees, the sample promises a 100% refund of all files after payment. Read that line twice. It is not a money-back policy. It is a promise to give the files back, dressed in the word refund so it sounds like a store. 100% is a round number chosen to end the conversation. Refund is a word real shops print on receipts. Neither word is a warranty you can take to a bank.

The same block also says they guarantee fast decryption, security, and anonymity. Fast is a rush. Security is a lullaby. Anonymity is a hint that you should hide the payment. None of those words rebuild 1.jpg.[2AF20FA3].[teamblding@outlook.com].osa. A 100% line on a criminal flyer is still a 0% contract. You cannot leave a review on teamblding@outlook.com.

Do not treat that percentage as a reason to pay. Do not treat it as a reason to mail the inbox “just to ask how the 100% works.” Asking is the product. The CISA StopRansomware Guide is blunt about this kind of squeeze. Paying does not ensure the files come back, does not ensure the systems are clean, and does not ensure anyone on the other side keeps a promise.

YOUR ID is blank, and there is no numeric clock

The sample ends with YOUR ID: and then a dash. That blank is not a puzzle you should finish. Do not invent a number because other Makop notes print one. Do not copy 2AF20FA3 from the filename into that field and mail it as if you were filling a form. The ID in the filename is already sitting on disk. The blank on the flyer is part of the costume. Leave both as they are.

The sample also has no 48-hour clock. It has no 72-hour leak fuse. It has no 7-day key threat. Other families use timers so you feel managed. This flyer skips the digits and goes straight to Stolen, pay for decrypt, and teamblding@outlook.com. You are supposed to feel that waiting is already a mistake. Do not add a fuse because a forum post said “they only wait two days.” The published note did not print one. Leave the fuse uninvented.

This locker is not a real OSA organization

Three letters on a file ending are a brand, not a company. Osa ransomware is the locker that appends .osa, drops +README-WARNING+.txt, and prints teamblding@outlook.com. It is not the Optical Society. It is not a clinic. It is not a school district. It is not a software vendor whose logo happens to use OSA. Do not smear those organizations because a malware family reused the letters. Do not call a real help desk and ask them to decrypt your .osa pile. They did not lock the files. They cannot unlock them. Name the locker when you write the incident down, so the next person does not spend an hour hunting a living org that was never in the room.

If a later helper says “we already talked to OSA,” ask which OSA they mean. If they mean the locker, they are selling a conversation with criminals. If they mean a real organization, they are mixing the nickname on purpose so you panic into a deposit. Either way, do not pay. Keep the artifacts: one locked sample such as 1.jpg.[2AF20FA3].[teamblding@outlook.com].osa, and a copy of +README-WARNING+.txt. Those two files identify the strain. A press release from a real OSA shop does not.

How The Attack Works

The shop is simple once you stop reading it as a rescue. Lock the files. Brand the names with an ID, an inbox, and .osa. Drop a README wrapped in WARNING tape. Shout Encrypted and Stolen. Point the scared person at teamblding@outlook.com. Promise a 100% refund of files. Skip the $ figure. Skip the wallet. Skip the numeric clock. Then wait for someone else to sell a conversation.

1. The lock keeps the old name so you recognize the loss

Osa encrypts the files it wants as leverage, then appends a victim ID, the inbox, and .osa. That is why 1.jpg is still readable as 1.jpg.[2AF20FA3].[teamblding@outlook.com].osa. The operators want you to inventory the damage in seconds. They want you to see the vacation photo, the invoice, the tax sheet, and the family video in one glance. A coded filename can confuse you. A readable filename makes you feel the theft.

If only one folder looks wrong, do not assume the rest of the disk is safe. Ransomware walks trees. It hits Documents, Desktop, Pictures, Downloads, and any drive letter it can reach, including a USB stick you forgot was plugged in. Unplug extra disks. Do not plug in a copy “just to check.” Checking is how the extra copy gets the same .osa ending.

Double-clicking a renamed file does not bring the photo back. The thumbnail may already look broken. Excel may ask for a workbook that is still sitting in the same folder, only the bytes inside are no longer a workbook. That broken open is the first proof. The second proof is the extra ending plus the inbox in the name. Together they are enough. You do not need to mail teamblding@outlook.com to confirm what you are looking at.

2. +README-WARNING+.txt turns a break-in into a ticket

Once the names are branded, the malware needs a voice. +README-WARNING+.txt is that voice. It sits in the same folders as the locked files so the first sort puts help next to harm. On many machines a text file with plus signs sorts near the top. You open it because it looks like the only thing that still speaks English.

The body is short enough to finish before a relative walks into the room. Attention. What’s happened. Encrypted and Stolen. Contact us and pay for decrypt. Recommendation: strong encryption, do not rename, do not ask anyone else. Solution: mail teamblding@outlook.com. 100% refund of all files after payment. YOUR ID: blank. Each beat closes a door. The shout closes “maybe Windows just glitched.” The stolen line closes “maybe a backup will save me.” The inbox closes “maybe there is a local tool.” The 100% line closes “maybe I should wait overnight” by handing you a finished promise.

Notice what the note does not give you. It does not give you a company, a real refund policy, or a way to prove the other side will ever send a key. It does not give you a $ figure. It does not give you a wallet. It does not give you a Session handle or an onion. It does not give you a filled unique ID. It gives you a tone that says this is already decided. That tone is the product. Read the file as a sales flyer. Then close it. Keep it on disk.

3. Encrypted and Stolen is the opening shout

The first real sentence of the sample is a headline, not a technician. Files are Encrypted and Stolen names the disaster and the second squeeze in one breath. You are supposed to feel outmatched before you have even reached the contact line. Capital letters do that work. The word Stolen does that work. Together they make the inbox feel like the only adult move left.

The shout also travels. Search ads will recycle it. Commenters will paste it. A later “Osa helper” will recite it so they sound close to your Documents folder. Reciting a headline is not a decryptor. It is proof they can read. Keep the line as an identifier when you describe the incident. Do not treat it as a diagnosis you have to obey. Do not invent a leak site to make Stolen feel more complete. The sample never named one.

4. Do not delete, rename, or modify is a fence around the evidence

The Recommendation block tells you not to delete, rename, or modify encrypted files. Other methods cannot provide guarantees and may mislead you. Attempts to decrypt files using other methods and from other people will result in file corruption and loss of money. That paragraph has two jobs. The useful job is accidental: leaving the locked copies alone is actually good advice for a later trusted tool. The sales job is the rest of the sentence. Anyone other than us will ruin you. Don’t risk your money by turning to anyone other than us.

Take the first half. Leave 1.jpg.[2AF20FA3].[teamblding@outlook.com].osa named as it is. Leave +README-WARNING+.txt where it is. Do not run a random “osa unlocker” from an ad. Do not let a cousin “try a script.” Ignore the second half. “Anyone other than us” is how a criminal shop cancels every other adult in your life. A relative, an insurer, or an incident lead is not “other people” in the note’s sense. The people who locked the files do not get to pick your helpers.

5. teamblding@outlook.com is the door they want you to walk through

The recovery step in the sample is mail. Contact us by email: teamblding@outlook.com. That is the whole door. It looks like support because support uses email. Criminal shops use email too, because a thread is where a missing $ figure becomes a negotiation and a locked photo becomes a sample they asked you to attach.

Do not write that inbox. Do not create a throwaway account “just to see.” Do not send a screenshot of Explorer to prove the lock. They already chose the extension. They already chose the note name. They already printed the misspelling. A photo of +README-WARNING+.txt sitting next to 1.jpg.[2AF20FA3].[teamblding@outlook.com].osa does not make you a verified customer. It makes you a person still following the flyer.

If someone later says they will “talk to Osa for you” through that same address, that is a broker pitch. Brokers need you in the same funnel. You do not owe them a seat. Report the incident through official desks such as the Internet Crime Complaint Center if you are in the United States. Let counsel decide if contact is ever required for a specific legal reason. That decision is not yours to make from the Documents folder at midnight.

6. Pay for decrypt is checkout without a price tag

Plenty of lockers hide the figure until you write. This one does not print a $ amount at all. To decrypt the data you need contact us and to pay for decrypt. That broken English is the whole quote. There is no BTC line. There is no wallet. There is no “reasonable” number sitting on the page so you can round it into a parking ticket. The remaining step, in their script, is the mail. Once you write, they can name any $ figure they like, because you already answered.

A missing price is not kindness. It is a blank invoice. Do not fill it. Do not “ask what it costs.” Asking is how the blank becomes a number. Do not convert a later $ ask in your head into local currency and decide it is “not that much.” The number is theirs. The files are already locked. Another afternoon of panic will not change the bytes in 2.png.[2AF20FA3].[teamblding@outlook.com].osa.

Do not invent a victim $ figure because other Makop notes print one. Do not invent a wallet because a comment said “they always use Bitcoin.” The sample used for this page does not reprint either. This page will not invent them.

7. The wallpaper is extra theater, not a second note

The locker also changes the desktop wallpaper. That swap is meant to make the whole screen feel like a billboard so you cannot look away. A wallpaper is not a second set of instructions you have to obey. It is the same squeeze in a larger font. Do not photograph it into a group chat as if a clearer picture would unlock taxes.xlsx.[2AF20FA3].[teamblding@outlook.com].osa. Do not restore a pretty background and call the incident over. The locked names are still in Documents.

If the wallpaper text does not match +README-WARNING+.txt word for word, that is normal. One is a flyer you can copy. The other is a poster. Keep a screenshot of the desktop for the incident record if you still can. Then stop decorating. The evidence you actually need is the note file and one locked sample, not a prettier picture of the same threat.

8. Makop and Phobos are family labels, not a second key

Osa sits in the Makop family. Scanners also tag the same tree as Phobos. That is a family label, not a second locker on your disk, and not a public decryptor hiding under another name. A different family nickname in a scan log does not mean you should mail a different inbox. It does not mean a tool built for an older Phobos wave will open these .osa files. It means the shop reused a known kit and hung a new sign on it.

Family labels also travel in ads. Someone will sell a “Makop decryptor” or a “Phobos key” the week your folder breaks. Reciting Makop is not a key. Reciting Phobos is not a key. Reciting 2AF20FA3 is not a key. If a trusted project ever publishes a free decryptor for this strain, it will not need teamblding@outlook.com, and it will not need a $ deposit. Until then, treat any site that says “we already have the Osa key” as a second sales pitch.

9. Third parties will sell an Osa conversation

After a ransomware incident, search results fill up with companies that say they can decrypt Osa or “all .osa files.” Some of those shops are ordinary overpriced consultants. Plenty are a second scam. They will quote +README-WARNING+.txt so they sound close to the case. They will mention Encrypted and Stolen. They will mention the 100% refund line. They will mention teamblding@outlook.com as if they already called the original crew. They will ask for a sample file, a remote-access session, or a deposit.

A demo that “unlocks one file” is not proof they can unlock the vacation photo. Anyone can open one junk file they control. Anyone can send you a $ invoice that makes a payment window appear. A payment window is not Photos opening 1.jpg again. If a later message skips the original inbox and asks for coin over ordinary mail, that is still the same market, or a copycat standing in the same doorway. Do not answer. Do not help them invent a wallet the original flyer never printed.

A real public decryptor, when one exists, shows up on an official project page that already existed before your incident. It does not need a $ send. It does not need teamblding@outlook.com. If the pitch is “we can decrypt, pay us first,” you are still in the market the ransomware created. There is no public free decryptor known for this strain. Until a trusted project publishes one, treat any site that says “we already have the Osa key” as a second sales pitch.

10. Payment and mailing that inbox close nothing

Paying a stranger for a private key is not a guarantee. The people who send the note can take the $ and disappear. They can send a string that only makes a decryptor show an error. They can come back later and lock the same machine again. A mail thread makes that outcome easier, not harder. You cannot leave a review on a criminal inbox. The 100% refund line does not change that math.

Mailing teamblding@outlook.com is the free version of the same dead end. There is no public free decryptor known for this strain. Starting a thread does not rebuild a JPEG. It only keeps you in their story while the rest of the disk still needs a real plan.

If this is a company machine, tell counsel and your incident lead. If this is a home PC, tell the people whose files lived on it. Change passwords from a clean device. Watch bank and email alerts. Opening that inbox again is not useful work. It is the checkout, even when the flyer never printed a $ figure, a wallet, a Session ID, or an onion.

What To Do If Your Files End in .osa

Do not pay. Do not mail teamblding@outlook.com. Do not invent a Bitcoin address, a Session ID, an onion, or a victim $ figure to finish +README-WARNING+.txt. Do not “correct” the inbox spelling. Do not send proof of payment. Do not send a test file. If you already sent a message before you found this page, stop there. Do not pay a deposit to “hold the original price” for anyone who quotes the note.

• STEP 1: Use Rkill to terminate suspicious programs.
• STEP 2: Use Malwarebytes to remove for Ransomware and Unwanted Programs
• STEP 3: Use HitmanPro to remove Trojans and other Malware
• STEP 4: Use AdwCleaner to remove Malicious Browser Extensions and Adware
• STEP 5: Perform a final check with ESET Online Scanner
• STEP 6: Restore the files encrypted by ransomware

STEP 1: Use Rkill to terminate suspicious programs.

In this first step, we will download and run Rkill to terminate suspicious programs that may be running on your computer.

RKill is a program that was developed at BleepingComputer.com that attempts to terminate known malware processes so that your normal security software can then run and clean your computer of infections. When RKill runs it will kill malware processes and then removes incorrect executable associations and fixes policies that stop us from using certain tools.

1. Download Rkill.

   You can download RKill to your computer from the below link. When at the download page, click on the Download Now button labeled iExplore.exe. We are downloading a renamed version of Rkill (iExplore.exe) because some malware will not allow processes to run unless they have a certain filename.

   

   RKILL DOWNLOAD LINK
   (The above link will open a new page from where you can download Rkill)

2. Run RKill.

   After downloading, double-click the iExplore.exe icon to kill malicious processes. In most cases, downloaded files are saved to the Downloads folder.
   The program may take some time to search for and end various malware programs.

   

   When it is finished, the black window will close automatically and a log file will open. Do not restart your computer. Proceed to the next step in this guide.

STEP 2: Use Malwarebytes to remove Ransomware and Unwanted Programs

In this second step, we will install Malwarebytes to scan and remove any infections, adware, or potentially unwanted programs that may be present on your computer.

Malwarebytes is one of the most popular and trusted anti-malware tools for Windows — and it’s completely free for removing infections. It catches threats that many antivirus programs miss, including adware, browser hijackers, and trojans. Follow the steps below to scan and clean your PC in just a few minutes.

1. Download Malwarebytes

   Click the button below to download the latest version of Malwarebytes for Windows from the official source. The free version is all you need — it will scan your computer and remove adware, browser hijackers, and other malicious software at no cost.

   

   DOWNLOAD MALWAREBYTES FOR WINDOWS (FREE)
   
   (The link opens in a new page where your download will start)

2. Install Malwarebytes

   When the download finishes, open your Downloads folder and double-click the MBSetup file. If Windows shows a User Account Control pop-up, click “Yes” to allow the installation.

   

3. Follow the On-Screen Prompts to Install Malwarebytes

   The setup wizard will walk you through a few quick screens:

   • Choose where you’re installing the program — “Personal Computer” or “Work Computer” — then click Next.

     

   • Malwarebytes will now install on your device. This usually takes under a minute.

     

   • When installation is complete, the “Welcome to Malwarebytes” screen will open automatically.

     

   • On the final screen, click Open Malwarebytes to launch the program.

     

4. Enable “Scan for Rootkits”

   Before scanning, turn on rootkit detection so Malwarebytes can find even the most hidden threats. Click the Settings gear icon on the left side of the screen.

   

   In the settings menu, find “Scan for rootkits” and click the toggle so it turns blue.

   

   Done? Click “Dashboard” in the left pane to return to the main screen.

5. Start the Scan

   Click the blue Scan button. Malwarebytes will automatically update its virus database and start checking your computer for malware.

   

6. Wait for the Scan to Finish

   The scan checks your entire system for browser hijackers and other malicious programs, so it can take several minutes. Feel free to do something else — just check back occasionally to see the progress.

   

7. Quarantine the Detected Threats

   When the scan is done, you’ll see a list of everything Malwarebytes found — malware, adware, and potentially unwanted programs. Click the “Quarantine” button to remove all of them at once.

   

   Malwarebytes will now remove the malicious files and registry entries and move them safely into quarantine.

   

8. Restart Your Computer

   Some threats can only be fully removed after a reboot. If Malwarebytes asks you to restart, click Yes. Once you’re logged back in, your PC is clean and you can continue with the next steps in this guide.

   

STEP 3: Use HitmanPro to remove Rootkits and other Malware

In this third step, while the computer is in normal back, we will download and run a scan with HitmanPro to remove Trojans, rootkits, and other malicious programs.

HitmanPro is a second-opinion scanner — it’s designed to catch what your main antivirus might have missed. Instead of relying on a single detection engine, it checks the behavior of files in the locations where malware usually hides. Anything suspicious gets sent to the cloud, where it’s analyzed by two of the best antivirus engines available: Bitdefender and Kaspersky.

Good news: scanning is completely free, with no limits. You only need a license when it’s time to remove what was found — and even then, you can activate a free one-time 30-day trial to clean your PC at no cost. (A full license is $24.95 per year for 1 PC.)

1. Download HitmanPro

   Click the button below to download HitmanPro. Remember — the scan is free, so you have nothing to lose by checking your PC.

   DOWNLOAD HITMANPRO (FREE SCAN)
   (The link opens in a new page where your download will start)

2. Install HitmanPro

   When the download finishes, open your Downloads folder and double-click the file: “hitmanpro.exe” on 32-bit Windows, or “hitmanpro_x64.exe” on 64-bit Windows.

   

   If a User Account Control pop-up asks whether HitmanPro can make changes to your device, click “Yes” to continue.

   

3. Follow the On-Screen Prompts

   On the HitmanPro start screen, click “Next” to begin the system scan. No lengthy setup required — it goes straight to work.

   

   

4. Wait for the Scan to Finish

   HitmanPro will now check your computer for malicious programs. This usually takes just a few minutes thanks to its cloud-based scanning.
   

5. Review the Results and Click “Next”

   When the scan is done, HitmanPro will show you everything it found. Click “Next” to remove the detected threats.

   

6. Click “Activate Free License”

   To remove the malicious files, click the “Activate free license” button. This starts your free 30-day trial — no payment details needed — and unlocks the full cleanup.
   

   When the removal is complete, HitmanPro will show a summary of everything it cleaned. Click Next, then click Reboot if prompted. If there’s no reboot prompt, just click Close — your PC is clean.

STEP 4: Use AdwCleaner to remove Malicious Browser Extensions and Adware

In this next step, we will use AdwCleaner to remove malicious browser policies and unwanted browser extensions from your computer.

AdwCleaner is a free on-demand scanner that specializes in adware, browser hijackers, and unwanted toolbars — the exact threats that mainstream antivirus programs often miss. It also includes tools that repair the damage malware leaves behind, like hijacked browser settings and malicious policies. It’s a quick scan that’s well worth running.

1. Download AdwCleaner

   Click the button below to download AdwCleaner — it’s free, portable, and requires no installation.

   

   DOWNLOAD ADWCLEANER (FREE)
   (The link opens in a new page where your download will start)

2. Run AdwCleaner

   Open your Downloads folder and double-click the file named “adwcleaner_x.x.x.exe“. There’s no installation — the program starts right away.
   

   If Windows asks whether you want to allow AdwCleaner to run, click “Yes“. When the license agreement appears, click I agree to continue.

   

3. Enable “Reset Chrome policies”

   This setting removes malicious browser policies — a trick malware uses to lock your browser settings so you can’t change them back. Click “Settings” on the left side of the window, then turn on “Reset Chrome policies“.

   

4. Start the Scan

   Click “Dashboard” on the left side of the window, then click the “Scan” button.

   

5. Wait for the Scan to Finish

   AdwCleaner will now check your computer for adware and other malware. This usually takes only a few minutes — it’s one of the fastest scanners around.

   

6. Quarantine the Detected Threats

   When the scan finishes, AdwCleaner will list everything it found. Click the “Quarantine” button to remove all the malicious items at once.

   

7. Click “Continue” to Finish the Cleanup

   Save any open work first — AdwCleaner needs to close your open programs before it can clean. When you’re ready, click the “Continue” button.
   

   AdwCleaner will now delete all detected malware from your computer. If it asks you to restart your PC, allow it — your computer will be clean when you log back in.

STEP 5: Perform a final check with ESET Online Scanner

This final step involves installing and running a scan with ESET Online Scanner to check for any additional malicious programs that may be installed on the computer..

ESET Online Scanner is a free second-opinion scanner that performs a deep, full-system check for viruses, trojans, rootkits, and other malware. We use it as the final step because it’s thorough — if anything slipped past the previous scans, ESET will find it. A clean result here means your computer is malware-free.

1. Download ESET Online Scanner

   Click the button below to download ESET Online Scanner.

   

   DOWNLOAD ESET ONLINE SCANNER (FREE)
   (The link opens in a new page where your download will start)

2. Run the Installer

   When the download finishes, open your Downloads folder and double-click “esetonlinescanner.exe“.
   

3. Install ESET Online Scanner

   On the start screen, select your language from the drop-down menu and click Get started.

   

   On the Terms of use screen, click Accept.
   

   Choose your preferences for the Customer Experience Improvement Program and the Detection feedback system (either choice is fine), then click Continue.
   

4. Start a Full Scan

   Click Full Scan — this checks your entire computer, not just the common hiding spots.

   

   Select Enable for Detection of Potentially Unwanted Applications — this lets ESET catch adware and bundled junk programs, not just viruses. Then click Start scan.

   

5. Wait for the Scan to Finish

   ESET will now check every file on your computer. Because it’s a full scan, this can take a while — often an hour or more, depending on how much data you have. Leave it running in the background and check on it from time to time.

   

6. Review the Results

   When the scan completes, the Found and resolved detections screen appears. Any threats found were automatically cleaned and quarantined — there’s nothing extra you need to do. Click View detailed results if you want to see exactly what was removed.
   

   If ESET found nothing — congratulations, your computer has passed the final check and is malware-free.

STEP 6: Restore the files encrypted by ransomware

Unfortunately, in most cases, it’s not possible to recover the files encrypted by this ransomware virus because the private key which is needed to unlock the encrypted files is only available through the attackers. However, below we’ve listed three options you can use to try and recover your files.

Option 1: Search a decryption tool for this ransomware

The cybersecurity community is constantly working to create ransomware decryption tools, so you can try to search these sites for updates:

• https://id-ransomware.malwarehunterteam.com/
• https://decrypter.emsisoft.com/
• https://noransom.kaspersky.com/
• https://www.avast.com/ransomware-decryption-tools

Option 2: Use EaseUS Data Recovery Wizard Free to recover the encrypted files

EaseUS Data Recovery Wizard Free can restore files and repair corrupted files with simple clicks. Its powerful scanning algorithms can identify and retrieve huge file type library, including all of the popular video files, audio files, photos, and document formats.
While the free version only allows you to recover 2 GB of data, this can be helpful to see if the recovery is possible and restore back the most important files from your computer.

1. Download EaseUS Data Recovery Wizard Free.

   You can download EaseUS Data Recovery Wizard Free by clicking the link below.

   

   EASEUS DATA RECOVERY WIZARD FREE DOWNLOAD LINK
   (The above link will open a new page from where you can download EaseUS Data Recovery Wizard)

2. Double-click on the EaseUS Data Recovery Wizard Free setup file.

   When EaseUS Data Recovery Wizard Free has finished downloading, double-click on the setup file to install EaseUS Data Recovery Wizard on your computer. In most cases, downloaded files are saved to the Downloads folder.

   

   You may be presented with a User Account Control pop-up asking if you want to allow EaseUS to make changes to your device. If this happens, you should click “Yes” to continue with the EaseUS Data Recovery Wizard Free installation.

3. Follow the on-screen prompts to install EaseUS Data Recovery Wizard.

   When the EaseUS Data Recovery Wizard installation begins, click on the “Install Now” as seen in the image below.
   

   When your EaseUS Data Recovery Wizard installation completes, click the “Start Now” button to start the program.
   

4. Select a location to start recovering the encrypted files.

   Choose the drive or folder where you are the encrypted files that you want to recover and click “Scan“.
   

5. Wait for the EaseUS Data Recovery Wizard scan to complete.

   EaseUS Data Recovery Wizard will now scan your computer files that can be restored. This process can take a few minutes, so we suggest you do something else and periodically check on the status of the scan to see when it is finished.
   

6. Find the files you want to recover.

   When the EaseUS Data Recovery Wizard scan is finished scanning it will show a screen that displays the files that can be recovered. This tool can recover a lot of data, use the “Filter” button to quickly filter specific file types and find the files that you want to recover.
   

   Click the “Preview” button or double-click on a file for a full preview.
   

7. Select your files and click “Recover”.

   Finally, select the the files you want to recover and click “Recover“.
   
   Choose a safe location to save all the files.
   
   The free version only allow you to recover 2 GB of data, however, this will allow you to recover the most important files and see if EaseUS Data Recovery Wizard can correctly recover them.
   

Option 3: Try to restore your files with ShadowExplorer

This ransomware will attempt to delete all shadow copies when you first start any executable on your computer after becoming infected. Thankfully, the infection is not always able to remove the shadow copies, so you should continue to try restoring your files using this method.

1. Download ShadowExplorer.

   You can download ShadowExplorer from the below link.

   SHADOW EXPLORER DOWNLOAD LINK
   (This link will open a new web page from where you can download “ShadowExplorer”)

2. Install ShadowExplorer.

   Double-click on the ShadowExplorer-x.x-setup file to start the installation process, then follow the on-screen promts to install this program.
   

3. Select snapshot date.

   Open ShadowExplorer and then from the top bar select the drive where the files that you want to save are located, then select from the snapshot available one previous to this infection.

   

4. Export the files that you want to recover.

   Once you have found a copy of the original file or folder, right-click on it and the select “Export”. A window will prompt you where you want to save the file or folder.
   

Keep every .osa name exactly as it is. Do not bulk-rename 1.jpg.[2AF20FA3].[teamblding@outlook.com].osa back to 1.jpg, or 2.png.[2AF20FA3].[teamblding@outlook.com].osa back to 2.png, or invoice-2026.pdf.[2AF20FA3].[teamblding@outlook.com].osa back to a normal PDF, or taxes.xlsx.[2AF20FA3].[teamblding@outlook.com].osa back to a spreadsheet, or family.mp4.[2AF20FA3].[teamblding@outlook.com].osa back to a video. Stripping the extra ending is not a repair. It can make a later trusted tool worse, not better. The original name is already sitting in front of .osa. You do not need to edit it to know what you lost.

Keep +README-WARNING+.txt with the locked files, and keep at least one .osa sample next to it. Do not “clean up” every copy of the note. Do not fill in YOUR ID so the flyer looks complete. Do not drop the plus signs. The blank ID, the misspelled inbox, and the Stolen line are part of how you prove this was this strain and not a different locker that only sounds similar. Keep the contact marks as identifiers: teamblding@outlook.com, the 2AF20FA3 tag, and the 100% refund line. Those artifacts are evidence. They are not instructions you should carry out.

Do not pay. Do not mail that inbox. Do not ask a friend to write them “just to see.” A calm address is still the people who locked the files. This is not a real OSA organization. If a later message quotes +README-WARNING+.txt and offers “the real wallet,” that is still the same shop. If a later message skips the original inbox and asks for $ over a different address, that is still the same shop, or a copycat standing in the same doorway.

If someone claims they can already decrypt Osa files for a fee because they can recite Encrypted and Stolen and the 100% refund line, they are selling a report, not a key. If they mention teamblding@outlook.com as proof they “already called the crew,” they read the same note you did. Do not answer. Do not complete their checkout. Do not help them fix the flyer. Do not help them smear a living OSA org that was never part of this locker.

If Windows still offers to pick an app for the .osa type, decline it. There is no player for that ending.

The Bottom Line

Osa ransomware is a locker with a readable filename, a README wrapped in WARNING tape, and a checkout that names one misspelled inbox. It keeps the old name, stamps [2AF20FA3] and [teamblding@outlook.com], and appends .osa. 1.jpg becomes 1.jpg.[2AF20FA3].[teamblding@outlook.com].osa. The note is +README-WARNING+.txt. It shouts Encrypted and Stolen, points you at teamblding@outlook.com, and promises a 100% refund of all files after payment. There is no printed $ ransom. There is no wallet. There is no Session. There is no onion. There is no numeric clock. There is no public free decryptor known for this strain. The locker sits in the Makop family, also tagged as Phobos. The locker is not a real OSA organization.

Do not pay. Do not mail that inbox. Do not invent a wallet. Do not rename the pile in bulk. Keep +README-WARNING+.txt and a .osa sample. If you take one sentence with you, take this. A folder of names ending in .osa, plus +README-WARNING+.txt with an Encrypted and Stolen shout and teamblding@outlook.com, is ransomware on the first sighting. Treat it that way before anyone offers to fill the blank ID or smear a living org that shares three letters.