Because of the publicity that viruses have received, it is easy to blame any computer problem on a Virus. The following are not likely to be caused by a virus or other malicious code:
1) Hardware problems. There are not viruses that can physically damage computer hardware, such as chips, boards, and monitors.
2) The computer beeps at startup with no screen display.
3) You have two antivirus programs installed and one of them reports a virus. While this could be a virus, it can also be caused by one antivirus program detect the other program’s signatures in memory.
4) Often Microsoft Word warns that a document contains a macro. This does not mean that the macro is a virus.
5) You are not able to open a particular document. This is not necessarily an indication of a virus. Try opening another document or backup of the document in question. If other documents open correctly, the document may be damaged.
6) When running ScanDisk, Anti Virus Auto-Protect reports virus-like activity.
Besides these there are some programs, which are often mistaken for viruses.
Following three programs exhibit malicious behavior but not classified as virus:
A Trojan horse program is malicious program that pretends to be benign application; a Trojan horse program purposefully does something the user does not expect. Trojans are not viruses since they do not replicate, but Trojan horse programs can be just as destructive.
Many people use the term to refer only to no-replicating malicious programs, thus making a distinction between Trojans and viruses. The PWSteal.Trojan is a Torjan.
Worms are parasitic computer programs that replicate, but unlike viruses, do not infect other computer program files. Worms can create copies on the same computer, or can send the copies to other comuters via a network. Worms often spread via IRC (Internet Relay Chat)
PrettyPark.Worm is a particularly prevalent example.
Hoaxes are not viruses, but are usually deliberate or unintentional e-messages warning people about a virus or other malicious software program. Some hoxes cause as much trouble as viruses by causing massive amounts of unnecessary e-mail.
Most hoaxes contain one or more of the following characteristics:
- Warnings about alleged new viruses and its damaging consequences;
- Demands the reader forward the warning to as many people as possible’
- Pseudo-technical “information” describing the virus;
- Bogus comments from officials: FBI, software firms, news agencies, etc.