Virus infects worm by mistake
Ten years ago, there was a clear-cut distinction between Trojans, viruses and worms. They all had their own features specific to one family of malware only. As more people connected to the internet, cyber-criminals started mixing ingredients to maximize impact. And here I’m thinking Trojans with worm capabilities or viruses with Trojan features, and so on.
Now, another “practice” has silently emerged: the file infector that accidentally parasites another e-threat. A virus infects executable files; and a worm is an executable file. If the virus reaches a PC already compromised by a worm, the virus will infect the exe files on that PC - including the worm. When the worm spreads, it will carry the virus with it. Although this happens unintentionally, the combined features from both pieces of malware will inflict a lot more damage than the creators of either piece of malware intended.
While most file infectors have inbuilt spreading mechanisms, just like Trojans and worms (spreading routines for RDP, USB, P2P, chat applications, or social networks), some cannot replicate or spread between computers. And it seems a great idea to “outsource” the transportation mechanism to a different piece of malware (i.e. by piggybacking a worm).
Most likely these Frankenmalware, or “malware sandwiches,” take place spontaneously. The virus actually infects by mistake another piece of malware and ends up using its capabilities to spread. Bitdefender’s Antimalware Lab identified no less than 40,000 such malware symbioses out of a sample pool of 10 million files. One such case is the Virtob file infector, whose malicious code has been found infecting worms like OnlineGames, the ancient Mydoom or the more advanced Bifrose backdoor Trojan.
http://www.malwarecity.com/blog/virus-infects-worm-by-mistake-1246.html
(Should there be a "Virus" section under "Computers". I don't know if this quite fits into this category.)
= new reply since forum marked as read
Darwin says "hi!"
I remember reading about that.
And mitochondria have turned out to be a very important genetic analysis tool.
Adware hogs the shit out of your bandwidth. Trojans can be humorous (like "CupHolder"
or malicious. Viruses can cause destruction or hide in the background capturing secret information. Worms pretty much concentrate on spreading themselves but can have any of the other characteristics.
They're all created by malcreants (as I call them) and you don't want any of that shit on your computer. The fact that they are piggybacking (symbioses is a perfect term) is not a shock. It was destined to happen. I believe the creators merely have an objective in mind, insidious, damaging, financial gain, or just simple ego, and determine the means to create the infection based on the techniques they are most familiar with. You really can't classify them as anything other than "I didn't want that on my machine!!!" and how they got there is generally not easy to determine. The "virus" checking programs are always a few steps behind. They release updates in a reactive way, not a proactive one. The malcreants are always a few steps ahead.
On a humorous note: One of my late mentors liked to say that he would classify Windows as a virus except that viruses tend to actually DO something.