Remove "Ads By PDFdefault" Adware (Virus Removal Guide)

PDFdefault is an adware program that displays pop-up ads and unwanted advertisements on web pages that you visit. These advertisements will be shown as boxes containing coupons, as underlined keywords (in-text ads), pop-up ads or advertising banners.

What is PDFdefault?

PDFdefault is advertised as program that will improve your browsing experience while online. Though this may sound like a useful service, the PDFdefault program can be intrusive and will display advertisements whether you want them to or not.

The PDFdefault advertisements may have a different text under the pop-up: “Powered by PDFdefault“, “Brought to you by PDFdefault“, “RocketTab powered by PDFdefault“, “Ads by PDFdefault” or “Ads powered by PDFdefault“.

These ads are aimed to promote the installation of additional questionable content including web browser toolbars, optimization utilities and other products, all so the PDFdefault publisher can generate pay-per-click revenue.

When your machine is infected with the PDFdefault adware, other common symptoms include:

Advertising banners are injected with the web pages that you are visiting.
Random web page text is turned into hyperlinks.
Browser popups appear which recommend fake updates or other software.
Other unwanted adware programs might get installed without the user’s knowledge.

To make matters worse, you will also find that PDFdefault will cause your computer to act more sluggish or for your web browser to freeze.

How did PDFdefault get on my computer?

PDFdefault is commonly bundled with other free programs that you download off of the Internet. Unfortunately, some free downloads do not adequately disclose that other software will also be installed and you may find that you have installed PDFdefault without your knowledge.

You should always pay attention when installing software because often, a software installer includes optional installs, such as this PDFdefault adware. Be very careful what you agree to install.
Always opt for the custom installation and deselect anything that is not familiar, especially optional software that you never wanted to download and install in the first place.
It goes without saying that you should not install software that you don’t trust.

How to remove PDFdefault adware (Uninstall Guide)

This page is a comprehensive guide which will remove PDFdefault adware and other malicious programs that may be installed on your machine.
Please perform all the steps in the correct order. If you have any questions or doubt at any point, STOP and ask for our assistance.

To remove PDFdefault Ads, follow these steps:
STEP 1: Uninstall PDFdefault 1.0 from Windows
STEP 2: Scan your computer with AdwCleaner
STEP 3: Scan your computer with Malwarebytes Anti-Malware
STEP 4: Double-check for malware with HitmanPro

STEP 1 : Uninstall PDFdefault 1.0 from Windows

In this first step, we will try to identify and remove any malicious program that might be installed on your computer.

Go to the uninstall menu.
Windows 10 or Windows 8
1. To uninstall a program on Windows 10 or Windows 8, right-click on the Windows Start button and choose “Control Panel” from the pop-up menu.
2. When the “Control Panel” window opens click on the “Uninstall a program” option under “Programs” category.
Windows 7 or Windows Vista
1. If you are using Windows XP, Windows Vista or Windows 7, click the “Start” button, then click on the “Control Panel” menu option.
2. When the “Control Panel” window opens click on the “Uninstall a program” option under “Programs” category.
When the “Programs and Features” screen is displayed, scroll through the list of currently installed programs and uninstall “PDFDEFAULT 1.0” .
The malicious program may have a different name on your computer. To view the most recently installed programs, you can click on the “Installed On” column to sort your program by the installation date. Scroll through the list, and uninstall any unwanted or unknown programs.

If you are having issues while trying to uninstall the PDFdefault program, you can use Revo Uninstaller to completely remove this unwanted program from your machine.

If you cannot find any unwanted or unknown programs on your machine, then you can proceed with the next step.

STEP 2: Scan your computer with AdwCleaner

AdwCleaner is a free utility, which will scan your computer and web browser for the “Ads by PDFdefault” adware.

You can download AdwCleaner from the below link.
ADWCLEANER DOWNLOAD LINK (This link will open a new web page from where you can download “AdwCleaner”)
Before starting AdwCleaner, close your web browser, then double-click on the AdwCleaner icon.

If Windows prompts you as to whether or not you wish to run AdwCleaner, please allow it to run.
When the AdwCleaner program will open, click on the “Scan” button as shown below.

AdwCleaner will now start to search for the PDFdefault adware and other malicious files that may be installed on your computer.
To remove the malicious files that were detected in the previous step, please click on the “Cleaning” button.
AdwCleaner will prompt you to save any open files or documents, as the program will need to reboot the computer to complete the cleaning process. Please do so, and then click on the “OK” button.

When your computer reboots and you are logged in, AdwCleaner will automatically open a log file that contains the files, registry keys, and programs that were removed from your computer.

STEP 3: Scan your computer with Malwarebytes Anti-Malware

Malwarebytes Anti-Malware is a powerful on-demand scanner which will remove the PDFdefault adware from your machine. It is important to note that Malwarebytes Anti-Malware will run alongside antivirus software without conflicts.

You can download download Malwarebytes Anti-Malware from the below link.
MALWAREBYTES ANTI-MALWARE DOWNLOAD LINK (This link will open a new web page from where you can download “Malwarebytes Anti-Malware Free”)
Once downloaded, close all programs, then double-click on the icon on your desktop named “mbam-setup” to start the installation of Malwarebytes Anti-Malware.

You may be presented with a User Account Control dialog asking you if you want to run this file. If this happens, you should click “Yes” to continue with the installation.
When the installation begins, you will see the Malwarebytes Anti-Malware Setup Wizard which will guide you through the installation process.

To install Malwarebytes Anti-Malware on your machine, keep following the prompts by clicking the “Next” button.
Once installed, Malwarebytes Anti-Malware will automatically start and you will see a message stating that you should update the program, and that a scan has never been run on your system. To start a system scan you can click on the “Scan Now” button.
Malwarebytes Anti-Malware will now start scanning your computer for the PDFdefault adware. When Malwarebytes Anti-Malware is scanning it will look like the image below.
When the scan has completed, you will be presented with a screen showing the malware infections that Malwarebytes Anti-Malware has detected. To remove the malicious programs that Malwarebytes Anti-malware has found, click on the “Remove Selected” button.

Please note that the infections found may be different than what is shown in the image.
Malwarebytes Anti-Malware will now quarantine all the malicious files and registry keys that it has found. When removing the files, Malwarebytes Anti-Malware may require a reboot in order to remove some of them. If it displays a message stating that it needs to reboot your computer, please allow it to do so.

After your computer will restart, you should open Malwarebytes Anti-Malware and perform another “Threat Scan” scan to verify that there are no remaining threats

STEP 4: Double-check for malware with HitmanPro

HitmanPro finds and removes malware, adware, bots, and other threats that even the best antivirus suite can oftentimes miss. HitmanPro is designed to run alongside your antivirus suite, firewall, and other security tools.

You can download HitmanPro from the below link:
HITMANPRO DOWNLOAD LINK (This link will open a new web page from where you can download “HitmanPro”)
Double-click on the file named “HitmanPro.exe” (for 32-bit versions of Windows) or “HitmanPro_x64.exe” (for 64-bit versions of Windows). When the program starts you will be presented with the start screen as shown below.

Click on the “Next” button, to install HitmanPro on your computer.
HitmanPro will now begin to scan your computer for the PDFdefault malware.
When it has finished it will display a list of all the malware that the program found as shown in the image below. Click on the “Next” button, to remove malware.
Click on the “Activate free license” button to begin the free 30 days trial, and remove all the malicious files from your computer.

Your computer should now be free of the PDFdefault adware infection. You can now remove AdwCleaner from your machine, however we recommend that you keep HitmanPro and Malwarebytes Anti-Malware installed and perform regular computer scans.

If you are still experiencing problems while trying to remove PDFdefault pop-up ads from your machine, please do one of the following:

Run a system scan with Zemana AntiMalware
Start a new thread in our Malware Removal Assistance forum.

10 Rules to Avoid Online Scams

Here are 10 practical safety rules to help you avoid malware, online shopping scams, crypto scams, and other online fraud. Each tip includes a quick “if you already got hit” action.

Stop and verify before you click, log in, download, or pay.

Most scams win by creating urgency. Verify using a trusted method: type the website address yourself, use the official app, or call a known number (not the one in the message).

If you already clicked: close the page, do not enter passwords, and run a malware scan.
Keep your operating system, browser, and apps updated.

Updates patch security holes used by malware and malicious ads. Turn on automatic updates where possible.

If you saw a scary “update now” pop-up: close it and update only through your device settings or the official app store.
Use layered protection: antivirus plus an ad blocker.

Antivirus helps block malware. An ad blocker reduces scam redirects, phishing pages, and malvertising.

If your browser is acting weird: remove unknown extensions, reset the browser, then run a full scan.
Install apps, software, and extensions only from official sources.

Avoid cracked software, “keygens,” and random downloads. During installs, choose Custom/Advanced and decline bundled offers you do not recognize.

If you already installed something suspicious: uninstall it, restart, and scan again.
Treat links and attachments as untrusted by default.

Phishing often impersonates delivery services, banks, and popular brands. If it is unexpected, do not open attachments or log in through the message.

If you entered credentials: change the password immediately and enable 2FA.
Shop safely: research the store, then pay with protection.

Be cautious with brand-new stores, “closing sale” stories, and prices that make no sense. Prefer credit cards or PayPal for dispute options. Avoid wire transfers, gift cards, and crypto payments.

If you already paid: contact your card issuer or PayPal quickly to dispute the transaction.
Crypto rule: never pay a “fee” to withdraw or recover money.

Common patterns include fake profits, then “tax,” “gas,” or “verification” fees. Another is a “recovery agent” who demands upfront crypto.

If you already sent crypto: stop paying, save evidence (wallet addresses, TXIDs, chats), and report the scam to the platform used.
Secure your accounts with unique passwords and 2FA (start with email).

Use a password manager and unique passwords for every account. Enable 2FA using an authenticator app when possible.

If you suspect an account takeover: change passwords, sign out of all devices, and review recent logins and recovery settings.
Back up important files and keep one backup offline.

Backups protect you from ransomware and device failure. Keep at least one backup on an external drive that is not always connected.

If you suspect infection: do not connect backup drives until the system is clean.
If you think you are a victim: stop losses, document evidence, and escalate fast.

Move quickly. Speed matters for disputes, account recovery, and limiting damage.
- Stop payments and contact: do not send more money or respond to the scammer.
- Call your bank or card issuer: block transactions, replace the card if needed, and start a dispute or chargeback.
- Secure your email first: change the email password, enable 2FA, and remove unfamiliar recovery options.
- Secure other accounts: change passwords, enable 2FA, and log out of all sessions.
- Scan your device: remove suspicious apps or extensions, then run a full malware scan.
- Save evidence: screenshots, emails, order pages, tracking pages, wallet addresses, TXIDs, and chat logs.
- Report it: to the payment provider, marketplace, social platform, exchange, or wallet service involved.

These rules are intentionally simple. Most online losses happen when decisions are rushed. Slow down, verify independently, and use payment methods and account controls that give you recourse.

Remove “Ads by PDFdefault” adware (Virus Removal Guide)