Automatic Disinfection Usually standalone malware (backdoors, worms, trojans, etc.) is automatically removed by F-Secure Anti-Virus (FSAV) starting from version 5.40. Malware files get automatically renamed by FSAV, so they cannot be started any more. In some rare cases, when automatic disinfection is not possible, a user can select disinfection action by him/herself to make FSAV rename or delete an infected file. In some special cases, it is recommended to use specific disinfection tools provided by F-Secure. They can be downloaded from our ftp site:
ftp://ftp.f-secure.com/anti-virus/tools/ F-Secure Anti-Virus can be purchased from our web shop or from our authorized distributors. A trial version F-Secure Anti-Virus, limited to 30 days, can be downloaded from our website:
http://www.f-secure.com/download-purchase/ All the latest versions of FSAV can download anti-virus database updates automatically. However, these updates can be also downloaded and installed manually from our web or ftp sites:
http://www.f-secure.com/download-purchase/updates.shtml Manual Disinfection To manually disinfect standalone malware (backdoors, worms, trojans, etc.) it is usually enough to delete all infected files from a computer and to restart it. Active malware files are usually locked by operating system so different disinfection approaches are required for different operating systems.
Please note that manual disinfection is a risky process, so it is recommended only for advanced users.
If Windows 95, 98 and ME operating system is used, it is recommended to restart a computer from a bootable system diskette and to delete an infected file from the command prompt. For example, if a malicious file named ABC.EXE is located in Windows folder, it is usually enough to type the following command at command prompt:
DEL C:\WINDOWS\ABC.EXE
and to press Enter. After that the infected file will be gone. If Windows NT, 2000 or XP is used, a malicious file has to be renamed with a different extension (for example .VIR) and then a system has to be restarted. After restarting, a renamed malicious file will no longer be active and it can be easily to delete manually.
Malware Disinfection Tools F-Secure provides disinfection tools for certain malware. These tools can be downloaded from this webpage:
http://www.f-secure.com/download-purchase/tools.shtml ftp://ftp.f-secure.com/anti-virus/tools/ Windows System Restore Issues If Windows ME or XP is used, it is recommended to disable System Restore feature of these operating systems to prevent a computer from re-infection by an already removed malware. The fact is that System Restore feature of these operating systems might save an infected file into the special folder and copies it back to a hard drive it every time it has been renamed or deleted by F-Secure Anti-Virus or by a user. Instructions on how to disable System Restore feature are here:
Windows ME:
http://www.f-secure.com/v-descs/sfc_dis.shtml Windows XP:
http://www.f-secure.com/v-descs/sfc_dis1.shtml It is recommended to re-enable System Restore after disinfection in order to restore stable system configuration if any crash or incompatibility issue occurs in the future.
Failed Disinfection In some cases, F-Secure Anti-Virus might not disinfect a system automatically. In this case, please visit our Support pages:
http://support.f-secure.com/enu/home/virusproblem/howtoclean/