W32/Opaserv.C
Analysis
- Virus is 32bit, with a size of 28,672 bytes and
is a minor variant to W32/Opaserv.A – the only
difference is in a couple of lines of code
- 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 ScrSvr.exe
and modifies the registry to load at Windows startup
–
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\
CurrentVersion\Run
ScrSvr = Windows\ScrSvr.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 ScrSvr.exe
-
The virus will modify the WIN.INI configuration file to load the dropped virus at Windows startup