Analysis by: Sabrina Lei Sioting
 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

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 modifies registry entries to disable the Windows Firewall settings. This action allows this malware to perform its routines without being deteted by the Windows Firewall.

  TECHNICAL DETAILS

File Size: 101,888 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 11 May 2011
Payload: Connects to URLs/IPs

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.

Other System Modifications

This Trojan modifies the following registry entries to disable the Windows Firewall settings:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
EnableFirewall = 0

(Note: The default value data of the said registry entry is 1.)

Other Details

This Trojan connects to the following URL(s) to check for an Internet connection:

  • http://google.com/

It connects to the following possibly malicious URL:

  • http://{BLOCKED}gcbh.ku3.in/t/d2hsdWF3OzJ0OHY5Oj0,cyJtIW8kaUVyam9zeHk9Tn5DSgIQAkxDUU1bFx0CHQAdCQECHQEABwVEDwgCDA0QCnVwcGUlM3tvJjwmJ2VrPC4jbGJ1MiA1PGVpfC4yNC9iUUcDAAcKEwkcVFpcShlTXkNBR0RNRENFQF8UGghAT1nk6Oa,tLW_5ri5uru8vb6_oKGiow==/count.htm

  SOLUTION

Minimum Scan Engine: 8.900
FIRST VSAPI PATTERN FILE: 8.148.12
FIRST VSAPI PATTERN DATE: 11 May 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

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\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
    • From: EnableFirewall = "0"
      To: EnableFirewall = "1"

Step 3

Scan your computer with your Trend Micro product to delete files detected as TROJ_AGENT.JHJ. 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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