Worm:W32/Kaxela.A

Classification

Category :

Malware

Type :

Worm

Aliases :

Worm:W32/Kaxela.A, Backdoor.Win32.Agent.msv, Worm:Win32/Winko.A (Microsoft), TROJ_NSPM.JR (Trend Micro), W32/Winko.worm.gen (McAfee), Packed.Generic.115 (Symantec)

Summary

Kaxela is a type of autorun worm that propogates through infected disks and removable drives. This means that a user must physically connect the disk or drive to their system to become infected.

Removal

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.

Technical Details

The worm infects the system by dropping a copy of itself and the autorun.inf file into the drive. During the infection process, the worm will make copies of itself and place them in various, randomly generated files, then delete the original copy of the worm.

Once installed, the worm will also attempt to connect to two sites, most likely in order to send information, to download malicious programs or to receive further commands.

File System Changes

Creates these files:

  • %System%\[Random].DLL
  • %System%\[Random].EXE
  • C:\autorun.inf
  • C:\auto.exe
  • %System%\delme.bat

Process Changes

Uses these temporary processes:

  • %System%\[Random].EXE

These modules were loaded into other processes:

  • %System%\[Random].DLL

Writes in memory of these processes:

  • %System%\services.exe
  • %System%\lsass.exe
  • %System%\svchost.exe

Network Connections

Attempts to download files from:

  • https://alexa.verynx.cn//[...]xa.txt

Attempts to connect to:

  • https://211.100.21.4/[..].cnt

Registry Modifications

Sets these values:

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\[random] = "%System%\[random].EXE -k"

Creates these keys:

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\[random]
  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\Root\LEGACY_[random]

Deletes these keys:

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\ERSvc