<b>W32/Sasser.worm.a</b>
Make sure everyone updates their virus defs... Otherwise our caps could be reached at the beginning of the month!!!
This worm spreads by exploiting a recent Microsoft vulnerability, spreading from machine to machine with no user intervention required.
This worm scans random IP addresses for exploitable systems. When one is found, the worm exploits the vulnerable system, by overflowing a buffer in LSASS.EXE. It creates a remote shell on TCP port 9996. Next it creates an FTP script named cmd.ftp on the remote host and executes it. This FTP script instructs the target victim to download and execute the worm (with the filename #_up.exe as aforementioned) from the infected host. The infected host accepts this FTP traffic on TCP port 5554.
The worm spawns multiple threads, some of which scan the local class A subnet, others the class B subnet, and others completely random subnets. The destination port is TCP 445.
<u><b>Manual Removal Instructions </b></u>
To remove this virus "by hand", follow these steps:
Reboot the system into Safe Mode (hit the F8 key as soon as the Starting Windows text is displayed, choose Safe Mode.
Delete the file AVSERVE.EXE from your WINDOWS directory (typically c:\windows or c:\winnt)
Edit the registry
Delete the "avserve" value from
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Reboot the system into Default Mode
Make sure everyone updates their virus defs... Otherwise our caps could be reached at the beginning of the month!!!
This worm spreads by exploiting a recent Microsoft vulnerability, spreading from machine to machine with no user intervention required.
This worm scans random IP addresses for exploitable systems. When one is found, the worm exploits the vulnerable system, by overflowing a buffer in LSASS.EXE. It creates a remote shell on TCP port 9996. Next it creates an FTP script named cmd.ftp on the remote host and executes it. This FTP script instructs the target victim to download and execute the worm (with the filename #_up.exe as aforementioned) from the infected host. The infected host accepts this FTP traffic on TCP port 5554.
The worm spawns multiple threads, some of which scan the local class A subnet, others the class B subnet, and others completely random subnets. The destination port is TCP 445.
<u><b>Manual Removal Instructions </b></u>
To remove this virus "by hand", follow these steps:
Reboot the system into Safe Mode (hit the F8 key as soon as the Starting Windows text is displayed, choose Safe Mode.
Delete the file AVSERVE.EXE from your WINDOWS directory (typically c:\windows or c:\winnt)
Edit the registry
Delete the "avserve" value from
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Reboot the system into Default Mode