Smibag is a multi-component worm that attempts to send itself using a localized version (Korean) of MSN messenger. The worm is sent as SMB.EXE file. The worm drops adware components to an infected hard drive.
Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.
A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:
Check for the latest database updates
First check if your F-Secure security program is using the latest updates, then try scanning the file again.
Submit a sample
After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.
Note: If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.
Exclude a file from further scanning
If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.
Note: You need administrative rights to change the settings.
The SMB.EXE file that is send via MSN Messenger is a dropper. Inside it contains a ZIP archive and a decompression utility. When the dropper is run, it drops UZ.EXE and EXT.ZIP files and runs UZ.EXE utility to decompress the archive.
The archive contains the following files:
admagic.exe - adware file atl.dll - legitimate Windows component msnvc.exe - file that sends the worm via MSN Messenger raw32x.dll - data file sm.dll- browser helper object file
The ADMAGIC.EXE file is then copied to the root of C: drive together with the dropper (SMB.EXE file). After that the UZ.EXE, ATL.DLL, RAW32X.DLL and SM.DLL files are copied to Windows System directory and the SM.DLL and ATL.DLL files are registered to Windows with Regsvr32.exe utility.
When the ADMAGIC.EXE adware file is run, it creates a startup key for itself in System Registry:
[HKLM\Software\Microsoft\Windows\CurrentVersion\Run] "svchost" = "c:\admagic.exe"
This file is supposed to open Internet Explorer every 5 minutes. But we did not observe this behaviour on our test system. The file has a few adult website links in its body.
The worm attempts to spread using MSN Messenger as SMB.EXE file. The file that does the actual sending is MSNVC.EXE.