Can malware (or other stuff like that) infect an entire network connection?

[Mr.DudeManPersonGuy]

Hey guys!

I'm pretty new here so please forgive me if I make a problem of the obvious, as I'm not that tech savvy (and forgive me if this post is too long, for just an inquiry).

Basically I just have a question (or two!). Is it possible for a malware-infected computer/laptop to infect an entire network connection? And if so how can it be fixed (for the entire network)?

While surfing the interwebs about malware and other viruses, I came across an article that says it's possible for other computers (within the same connection/within vicinity of) to be affected by malware from a malware-infected computer. (http://www.businessinsider.com.au/what-is-air-gap-malware-2014-3)

The article says the hacker has to be very skilled and such, but also the attack has to be specifically aimed at you. While this might be true I still think it's not the only way malware can transfer/spread from one system to another within a network connection. After reading the article, and thinking about it I sort of became paranoid. I remember a friend who had a malware problem on her desktop last year. She managed to fix everything but she also claimed that her MS Surface occurred to have the same problems (ie. ads on the sides, pop-up tab ads, etc.) when browsing the web. Welp, that's another question, too. Are there other ways for malware (or other stuff like that) to infect an entire network connection, given that it is possible?

So here are the questions:

1.) Is it possible for a malware-infected computer/laptop to infect an entire network connection?...
2.) ...and if so how can it be fixed (for the entire network)?
3.) Are there other ways for malware (or other stuff like that) to infect an entire network connection, given that it is possible?
4.) Is it even malware when an infected system affects other systems within the same network or is it another problem (eg. worms)?

*whoops, that went more than two questions!*

Thanks in advance!
- From a super paranoid guy who probably has over 9000 anti-viruses installed in his laptop. Thanks a lot internet.

 

[Mateotis]

Some worms are specified to do these, when you catch one on one of the computers, it's advised to check the others as well.

A hacker can also install a RAT (Remote Administration Tool) on your computer and possibly use it to try and infect the others in your network.

Most of the malware however do not have these capabilities, so no need to be paranoid about it.

 

[LucyN]

When you fix the network, you first have to disconnect all of the computers so that no other devices are affected. You'll have to fix each one separately, but at least after the first one, you know what you are looking for and it will go faster. Scan all of the computers and add them back to the network as they are cleared. If you are connecting through a server, definitely do that one first.

Watch out when a user opens an unexpected attachment, make sure it isn't someone spoofing your boss' email address! Watch out for Reply All. That can spread viruses too.

 

[Edward ST]

1) Yes, if you have an ad-hoc connection ( you are connected with other guys in a single point) you can have the risk to be infected. A single computer is enough to infect the entire connection (The strongest viruses at this chapter are Duqu or Stuxnet or anything like that).
2) If you are infected, you must install a strong security suite in order to disinfect your PC and, after that, you are advised to scan all PCs with the same suite. Don't forget to disconnect the PC from the internet. The security suite will find the viruses if they exist, and will clean the PCs.
3) DNS Spoofing, Worm-infecting way, and the DDOS are the most common ways.
4) Rewrite the question, I don't understand.

 

[Cowpipe]

Just to add an answer to your 4th question (if I understand correctly):

4.) Is it even malware when an infected system affects other systems within the same network or is it another problem (eg. worms)?

Yes, most commonly it is the malware that affected the original computer that 'copies itself over' to another computer on the network (malware that does this are what are generally called 'worms'). There are some exceptions, such as targeted attacks, but in general, as has been said before me, if you find out somebody's computer has been infected on the same network as you, it's safest to disconnect your computer from the network and run a virus scan (and disinfect if needs be). And of course, don't open any email attachments if somebody on your network has been infected

Finally, If you leave the computer connected to the network whilst you run the antivirus scan, there is always the chance the malware will copy itself over to a part of your computer that the antivirus has already scanned (sneaking past it), so while unlikely, it can happen so it's much better to disconnect first to run the scan. (also if you are infected, you don't want to go spreading it around even more )

Hope that helps