Summary

Summary
Action
More Information
| How it spreads |
|
|---|---|
| Affected operating systems | Windows |
| Characteristics |
|
| Protection available since | 2 December 2005 12:30:20 (GMT) |
| Detected by | All Sophos products |
- Endpoint Security and Control 9.0
- Small business solutions 4.0
Action

Summary
Action
More Information
Please follow the instructions for disinfecting PE executables.
More Information
W32/Mkar-A is a multicomponent prepending virus with backdoor functionality, that targets Windows PE EXE files.
W32/Mkar-A comprises the two executables: main host file and embedded UPX packed component.
W32/Mkar-A marks infected files by appending them with the following string:
"Mrak1pack..............."
W32/Mkar-A copies itself to the following files:
<Current Folder>\001\svchost.exe
<System>\Netstart\svchost.exe
where 001 and Netstart are folders created by the virus, and may create the files unpacker.exe and tmp.exe that are detected as components of the virus.
The following registry entry is set to run svchost.exe at start up:
HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
NetStart
<System>\NETSTART\svchost.exe"
Registry entries are created under:
HKLM\SOFTWARE\Microsoft\Mrak\
including the following:
HKLM\SOFTWARE\Microsoft\Mrak
ID = <random value>
HKLM\SOFTWARE\Microsoft\Mrak
OM = <random value>
