Analysis by: Karl Dominguez
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

It may be dropped by TROJ_DROPPER.ZBB.

It injects itself into specific processes as part of its memory residency routine. It connects to the following possibly malicious URL

This Trojan may be dropped by other malware. It may be dropped by other malware.

However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 176,128 bytes
File Type: DLL
Memory Resident: Yes
Initial Samples Received Date: 28 Mar 2011
Payload: Connects to URLs/IPs

Arrival Details

This Trojan may be dropped by other malware.

It may be dropped by the following malware:

  • TROJ_DROPPER.ZBB

Installation

This Trojan injects itself into the following processes as part of its memory residency routine:

  • opera.exe
  • firefox.exe
  • safari.exe
  • mozilla.exe
  • iexplore.exe

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\SSHNAS
Type = 20

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

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

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SSHNAS
ImagePath = %System%\svchost.exe -k netsvcs

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SSHNAS
DisplayName = SSHNAS

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SSHNAS\Parameters
ServiceDll = %System%\sshnas21.dll

Other System Modifications

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

HKEY_CURRENT_USER\Software\Microsoft\
ProcessStorage
wd29 = {hex value}

It adds the following registry keys as part of its installation routine:

HKEY_CURRENT_USER\Software\Microsoft\
ProcessStorage

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\SvcHost
netsvcs = 6to4 AppMgmt AudioSrv Browser CryptSvc DMServer DHCP ERSvc EventSystem FastUserSwitchingCompatibility HidServ Ias Iprip Irmon LanmanServer LanmanWorkstation Messenger Netman Nla Ntmssvc NWCWorkstation Nwsapagent Rasauto Rasman Remoteaccess Schedule Seclogon SENS Sharedaccess SRService Tapisrv Themes TrkWks W32Time WZCSVC Wmi WmdmPmSp winmgmt wscsvc xmlprov napagent hkmsvc BITS wuauserv ShellHWDetection helpsvc WmdmPmSN SSHNAS

(Note: The default value data of the said registry entry is 6to4 AppMgmt AudioSrv Browser CryptSvc DMServer DHCP ERSvc EventSystem FastUserSwitchingCompatibility HidServ Ias Iprip Irmon LanmanServer LanmanWorkstation Messenger Netman Nla Ntmssvc NWCWorkstation Nwsapagent Rasauto Rasman Remoteaccess Schedule Seclogon SENS Sharedaccess SRService Tapisrv Themes TrkWks W32Time WZCSVC Wmi WmdmPmSp winmgmt wscsvc xmlprov napagent hkmsvc BITS wuauserv ShellHWDetection helpsvc WmdmPmSN.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}g.com/tbd.php
  • http://{BLOCKED}y.com/tbd.php
  • http://{BLOCKED}life.com/tbd.php
  • http://{BLOCKED}l.com/oms.php
  • http://{BLOCKED}del.com/oms.php

However, as of this writing, the said sites are inaccessible.

  SOLUTION

Minimum Scan Engine: 8.900
VSAPI OPR PATTERN File: 7.937.00
VSAPI OPR PATTERN Date: 29 Mar 2011

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_FRAUDPAC.ZB

    TROJ_DROPPER.ZBB 

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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.

 
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • SSHNAS
  • In HKEY_CURRENT_USER\Software\Microsoft
    • ProcessStorage

Step 5

Restore this modified 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\SOFTWARE\Microsoft\Windows NT\CurrentVersion\SvcHost
    • From: netsvcs = 6to4 AppMgmt AudioSrv Browser CryptSvc DMServer DHCP ERSvc EventSystem FastUserSwitchingCompatibility HidServ Ias Iprip Irmon LanmanServer LanmanWorkstation Messenger Netman Nla Ntmssvc NWCWorkstation Nwsapagent Rasauto Rasman Remoteaccess Schedule Seclogon SENS Sharedaccess SRService Tapisrv Themes TrkWks W32Time WZCSVC Wmi WmdmPmSp winmgmt wscsvc xmlprov napagent hkmsvc BITS wuauserv ShellHWDetection helpsvc WmdmPmSN SSHNAS
      To: netsvcs = 6to4 AppMgmt AudioSrv Browser CryptSvc DMServer DHCP ERSvc EventSystem FastUserSwitchingCompatibility HidServ Ias Iprip Irmon LanmanServer LanmanWorkstation Messenger Netman Nla Ntmssvc NWCWorkstation Nwsapagent Rasauto Rasman Remoteaccess Schedule Seclogon SENS Sharedaccess SRService Tapisrv Themes TrkWks W32Time WZCSVC Wmi WmdmPmSp winmgmt wscsvc xmlprov napagent hkmsvc BITS wuauserv ShellHWDetection helpsvc WmdmPmSN

Step 6

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_FRAUDPAC.ZB. 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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