They're only viruses when they help Rydian's arguments.
Congrats on being entirely unhelpful yet again, but I'll respond.
Viruses are out there and more dangerous than ever*1, however the majority of things people get infected with are not viruses any more.
@[member='raulpica']
This includes modern rookits, which are their own category.
"Infection" =/= "virus". A virus is
a specific classification of infection. To be specific, a virus is a type of infection that spreads by embedding copies of itself into pre-existing files on the user's machine.
Hidrag.A is an example of a Virus, it copies itself into .exe files and relies on one of them being transferred to another machine, where, upon running, it resumes, infecting all the files on the new machine, and so on. Back in the P2P days where I ran across this, the basic technique was still very prevalent, and later on I actually found it in a Warez copy of Quake 2.
Nowadays, however, people are more cautious about transferring .exe files, and standard download procedures will scan and test files, so hoping somebody runs a random .exe that pops up has lower success rates than it did in the past. This is why modern types of infections have moved away from being viruses, and moved onto being malware (often scareware). Modern infections will generally take advantage of security holes that exist in client programs in order to automatically install themselves (for scareware, you almost always find them dropped in %appdata%/roaming), and they'll exploit flash, adobe reader, firefox, IE, chrome, whatever they can use to present themselves to the user that has write permissions
somewhere on the drive. Once they do that (since locations like %appdata% aren't protected by UAC), it's simple for them to launch and start changing settings.
As for the settings they change, there's one basic set of tactics that most infections (regardless of classification) take:
removal prevention. Back when viruses were the most common threat the settings changed were rather simple... disable windows update, kill explorer.exe, and the average person is freaked out.
Modern infections however, can take much stronger steps.
*1 - I cleaned up an infection a few weeks ago where a virus had actually uninstalled BITS and the windows update service from the system to make sure that the system couldn't be patched for security holes, since even the downloadable patches from MS use BITS. I had to copy clean versions of the related .dll files and re-register them in the command prompt to get BITS and WU working again to patch the system.
EDIT: My point is that the majority of what people actually get infected (at least initially*2) with initially are not viruses, because virus protection does it's job well enough.
*2 - Once the system's defenses are down it's usually "fair game" to other types of infections, which is why an infected machine usually has more than one uninvited guest.
@
BigOnYa:
