Hi can let everyone in on a few usefull bits of information that can explain many of the problems related to viruses and the way companies want you to believe there products work. In all honesty you need to know a little bit about your CPU and understand that a simple virus scan like Norton Antivirus will never work for people that download and surf more than usual.
Scanning misses many viruses. Your vendor happily tells you how many viruses your scanner detects, but fails to mention how many it misses. The viruses missed include "new" viruses written in the past 6 months (nearly half of all viruses) and older polymorphics that the vendor has still not mastered. For any scanner, it is easy for someone with a large collection of viruses to produce viruses the product misses.
Scanning can spread infection. Many viruses are now being written to infect on file open, file close, or directory traversal. Scanners do all these things. So when such a virus is resident, and not detected by your scanner, your scanner will actually spread the infection to everything you scan. If the scanner becomes infected, and does not let you know, then every time you scan, you will make things worse.
Critical files cannot be scannedCritical files cannot be scanned on the server by DOS-based scanners because they are already open. Such files are unlikely to be infected by a DOS virus, for if they are open at the time the virus tries to infect, the virus will be foiled. But the virus could get in at a time the file is not open, with the scanner subsequently failing to get a chance to look at the file.
A virus can spread throughout an entire network in seconds.virus can spread throughout an entire network in seconds. Thus detection by a scanner can be far too late. A common event is for an unwitting network supervisor with a virus such as Jerusalem.Sunday or SatanBug in memory to login and use the server. Everything they run becomes infected: LOGIN, MENU, ... LOGOUT. The next users to use any of these programs introduce the virus to their machine's memory, and will now infect anything they run from their hard disks, and any programs on the server which are in directories where they have write permission. A daily scan is not enough. In fact, a server scan done every 30 minutes is not often enough.
Resident scanners will generally fail to detect any stealth virus when the virus is resident. All stealth boot viruses and most stealth file viruses will load before the resident scanner, thwarting its good intentions.
In most products, a resident scanner large enough to scan for many viruses is too large for user memory; one small enough for memory must read from disk, and is thus too slow. Only a few resident scanners detect polymorphic viruses. In short, implementations of resident scanning are typically inept.
A resident scanner that interferes with user behavior will be removed by the user, no matter how successfully it interferes with viruses. Most resident scanners slow simple tasks such as file copy by a factor of 3 or more. If users wanted slower computers, they wouldn't be asking for new ones
Most scanners destroy some percentage of files or diskettes when told to remove particular viruses. Thus if you remove without first testing removal, you may cause more harm than good.
You can't learn anything about a virus if every copy of it is destroyed. You need to know more about the virus if you want to understand where it came from or why it keeps coming back. Removing the virus removes your ability to understand it.
For best results, use two or more anti-virus products."
Main points:
Anti-virus products typically false alarm on each other: number 1 leaves a scan string in memory; number 2 sees the string and thinks a virus is there. The false alarm is the result of poor coding on the part of both products, and the use of the same scan string often one that was published in a virus research journal.
Products that "inoculate" files may modify programs that perform self-checks, preventing the inoculated program from running. Products may try protecting each other, causing each self-check to fail.
All in all one must understand the new inviorment we work and play in today. This is the best step for living virus free. Learn how to surf!