Modified by: Sabrina Lei Sioting

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

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.

It executes the files it drops, prompting the affected system to exhibit the malicious routines they contain.

  TECHNICAL DETAILS

File Size: 39,944 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 09 Aug 2010

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.

Installation

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

  • %System%\scvhost.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_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
RsTray = "%System%\scvhost.exe"

It adds the following Image File Execution Options registry entries to automatically execute itself whenever certain applications are run:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
{application}
{application} = "svchost.exe"

Other System Modifications

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
{application}

Where {application name} may be any of the following:

  • 360Safebox.exe
  • 360tray.exe
  • AgentSvr.exe
  • CCenter.exe
  • DrUpdate.exe
  • FrameworkService.exe
  • KISSvc.exe
  • KPFW32.exe
  • KPfwSvc.exe
  • KVSrvXP.exe
  • KWatch.exe
  • KavStart.exe
  • MPMon.exe
  • MPSVC.exe
  • MPSVC1.exe
  • MPSVC2.exe
  • McProxy.exe
  • McTray.exe
  • MpfSrv.exe
  • QQDoctor.exe
  • QQDoctorRtp.exe
  • Rav.exe
  • RavMon.exe
  • RavMonD.exe
  • RavStub.exe
  • RavTask.exe
  • RegGuide.exe
  • RsAgent.exe
  • RsTray.exe
  • SHSTAT.exe
  • ScanFrm.exe
  • Uplive.exe
  • antiarp.exe
  • avp.exe
  • bdagent.exe
  • ccEvtMgr.exe
  • ccSetMgr.exe
  • ccSvcHst.exe
  • ccapp.exe
  • defwatch.exe
  • egui.exe
  • ekrn.exe
  • engineserver.exe
  • kmailmon.exe
  • livesrv.exe
  • mcagent.exe
  • mcinsupd.exe
  • mcmscsvc.exe
  • mcnasvc.exe
  • mcshell.exe
  • mcshield.exe
  • mcsysmon.exe
  • mcupdmgr.exe
  • mfeann.exe
  • mfevtps.exe
  • naPrdMgr.exe
  • rfwsrv.exe
  • rsnetsvr.exe
  • rtvscan.exe
  • safeboxTray.exe
  • udaterui.exe
  • vptray.exe
  • vsserv.exe
  • vstskmgr.exe
  • xcommsvr.exe
  • xcommsvr.exe

Dropping Routine

This Trojan drops the following files:

  • %Windows%\extext{random}t.exe
  • %System%\drivers\pcidump.sys

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

It executes the files it drops, prompting the affected system to exhibit the malicious routines they contain.

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}re.cn/xx8/Count.asp?mac={mac address}&ver={version}&os={OS}
  • http://{BLOCKED}3.cn/xx8/ttnew.txt

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 7.372.11
FIRST VSAPI PATTERN DATE: 09 Aug 2010

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

Restart in Safe Mode

[ Learn More ]

Step 3

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\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options
    • {application}

Step 4

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\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • RsTray = "%System%\scvhost.exe"

Step 5

Search and delete these files

[ Learn More ]
There may be some component files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden files and folders in the search result.
%Windows%\extext{random}t.exe
%System%\drivers\pcidump.sys

Step 6

Scan your computer with your Trend Micro product to delete files detected as TROJ_GERAL.SMW. 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.


Did this description help? Tell us how we did.

Related Malware