TROJ_SASFIS.XJ

 Modified by: Michael Cabel

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet


This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

File Size:

494,080 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

08 Sep 2012

Payload:

Drops files

Arrival Details

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Autostart Technique

This Trojan registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\ias
Type = 120

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\ias
Start = 2

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\ias
ErrorControl = 0

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\ias
ImagePath = %SystemRoot%\System32\svchost.exE -k ???s????h

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\ias
DisplayName = "swooqtim"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\ias
ObjectName = "LocalSystem"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\ias
Description = "Windows Sxitcway Firewall/Internet Connection Sharing (ICS)."

Other System Modifications

This Trojan adds the following registry entries as part of its installation routine:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\AppMgmt
FailureActions = {HEX Values}

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\FastUserSwitchingCompatibility
FailureActions = {HEX Values}

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\HidServ
FailureActions = {HEX Values}

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Messenger
FailureActions = {HEX Values}

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\NtmsSvc
FailureActions = {HEX Values}

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\RasAuto
FailureActions = {HEX Values}

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\RasMan
FailureActions = {HEX Values}

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\RemoteAccess
FailureActions = {HEX Values}

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\TapiSrv
FailureActions = {HEX Values}

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\WmdmPmSN
FailureActions = {HEX Values}

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Wmi
FailureActions = {HEX Values}

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\xmlprov
FailureActions = {HEX Values}

NOTES:

This Trojan drops the file %System Root%\{Random File Name}, which is also detected as TROJ_SASFIS.XJ. The dropped file then drops the malicious file %System Root%\Documents and Settings\All Users\Application Data\Storm\update\%SESSIONNAME%\{Random File Name}.cc3, which is detected as TROJ_AGENT_006420.TOMB.

It then executes the dropped file. As a result, routines of the said malicious file are then exhibited on the affected system.

  SOLUTION

Minimum Scan Engine:

9.200

FIRST VSAPI PATTERN FILE:

9.380.03

FIRST VSAPI PATTERN DATE:

08 Sep 2012

VSAPI OPR PATTERN File:

9.381.00

VSAPI OPR PATTERN Date:

09 Sep 2012

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Remove malware files dropped/downloaded by TROJ_SASFIS.XJ

    TROJ_AGENT_006420.TOMB

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Delete this registry key

[ 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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • ias

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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\AppMgmt
    • FailureActions = {HEX Values}
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\FastUserSwitchingCompatibility
    • FailureActions = {HEX Values}
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\HidServ
    • FailureActions = {HEX Values}
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Messenger
    • FailureActions = {HEX Values}
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NtmsSvc
    • FailureActions = {HEX Values}
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RasAuto
    • FailureActions = {HEX Values}
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RasMan
    • FailureActions = {HEX Values}
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RemoteAccess
    • FailureActions = {HEX Values}
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\TapiSrv
    • FailureActions = {HEX Values}
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WmdmPmSN
    • FailureActions = {HEX Values}
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Wmi
    • FailureActions = {HEX Values}
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\xmlprov
    • FailureActions = {HEX Values}

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_SASFIS.XJ. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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