As i working on my friend pc.he have both the virus protection Norton antivirus and And safe browser Mozzila Firefox. Sometime some people scaned his computer and get into his Document file. What is virus is it a programme file? and what language use to build it? How can we delet manually?
Pleas help me fixed this problem! Your help will be most appriciate.
a) Anti-virus tools only protect you against known viruses. b) Firefox might be more safe than MSIE, because of missing Active-X support, but not safe per se. c) How do you know the PC was scanned, and what did they did to which Document? d) Yes, a virus is a program, which is able to spread itself and infect other files. e) You may use nearly every language to build a virus. Empirically the virusses for the win-platform mostly occur as native .exe-files, which means they are compiled and linked, probably from c++/c source or VB. You should be able to write a virus in Java, but it will be hard to get the user infect himself and spread it. f) remove it with a current virusscanner, running from an uninfected OS, probably a linux-live-distro like ubuntu, knoppix, ... or remove the harddrive from the infected system, and scan from a different system, since some viruses may hide themself at runtime, kill or fool the virusscanner, and aren't removable due to some obscure windows file locking mechanism.
Normally it's a good advice to reinstall the whole system from scratch, if you got infected, because you will not be sure, that you successfully removed every malware.
If you get infected often, you could create a database of every file and create a md5-hashsum of it, to compare it after an infection. Then you should be allmost sure, that file x wasn't changed.
You should try to find out how you got infected to prevent in future.