W32/Opaserv.N
Analysis
- Virus is 32bit, with a size of 18853 bytes and is
a minor variant to W32/Opaserv.A
Virus icon is that of a standard 32bit executable
- Virus attempts to connect to opasoft.com and update
itself however the hard-coded URL is no longer available
- Virus copies itself to the Windows folder as MSTASK.EXE
and modifies the registry to load at Windows startup
–
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\
CurrentVersion\Run
mstask = Windows\MSTASK.EXE -
The virus will attempt to use SMB through NetBIOS seeking machines on the same IP subnet
-
The virus will scan IP addresses within the same domain for other shares, using NetBIOS via TCP port 137, seeking systems with open shares
-
If a system is found with an open share, the virus will copy itself to that machine in the Windows folder as MSTASK.EXE
-
The virus will modify the WIN.INI configuration file to load the dropped virus at Windows startup