TROJ_NSANTI.ZPS

April 24, 2013
 Analysis by: Christopher Daniel So
 PLATFORM:

Windows 2000, XP, Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: Yes

  • Encrypted: No

  • In the wild: Yes


  TECHNICAL DETAILS

File Size:

Varies

File Type:

PE

Memory Resident:

Yes

Initial Samples Received Date:

23 Aug 2010

Payload:

Drops files

Installation

This Trojan drops the following copies of itself into the affected system:

  • %System%\kavo.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
kava = %System%\kavo.exe

Other Details

This Trojan drops the following file(s)/component(s):

  • %System%\kav0.dll - detected as TROJ_NSANTI.ZPS
  • %User Temp%\exly.dll - detected as TROJ_AGENT.ARKV

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

  SOLUTION

Minimum Scan Engine:

8.900

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

Step 2

Remove the malware/grayware file dropped/downloaded by TROJ_NSANTI.ZPS

    TROJ_AGENT.ARKV

Step 3

Scan your computer with your Trend Micro product and note files detected as TROJ_NSANTI.ZPS

Step 4

Restart in Safe Mode

[ Learn More ]

Step 5

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • kava=%System%\kavo.exe


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