TROJ_TIJCONT.NIL

 Analysis by: Anthony Joe Melgarejo

 ALIASES:

TrojanDownloader:Win32/Tijcont.A (Microsoft), Downloader.Castov (Symantec), Mal/DelpDldr-F (Sophos), W32/Delf.F!tr.dldr (Fortinet), Trojan-Downloader.Win32.Tijcont (Ikarus), Win32/TrojanDownloader.Delf.RKR trojan (ESET)

 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:

  • 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 deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size:

Varies

File Type:

EXE, DLL

Memory Resident:

No

Initial Samples Received Date:

01 Jun 2013

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 and executes them:

  • {current malware directory}\svohcst.exe

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
Download = "{current malware directory}\svohcst.exe"

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}g.{BLOCKED}a.com.cn/s/blog_b2afd7fe01019tkf.html

It sets the attributes of the following file(s) to Hidden and System:

  • {current malware directory}\svohcst.exe

It deletes the initially executed copy of itself

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

9.954.03

FIRST VSAPI PATTERN DATE:

01 Jun 2013

VSAPI OPR PATTERN File:

9.955.00

VSAPI OPR PATTERN Date:

01 Jun 2013

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

Identify and terminate files detected as TROJ_TIJCONT.NIL

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 3

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
    • Download = "{current malware directory}\svohcst.exe"

Step 4

Scan your computer with your Trend Micro product to delete files detected as TROJ_TIJCONT.NIL. 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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