Analysis 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, Dropped by other malware

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: 61,799 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 24 Aug 2012
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.

Installation

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

  • %User Startup%\updates.exe
  • %Application Data%\updates\updates.exe

(Note: %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

It creates the following folders:

  • %Application Data%\updates

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
engel = "%Application Data%\updates\updates.exe"

Other System Modifications

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

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
DHCP = "1942370"

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
DNS =

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Associations
LowRiskFileTypes = ".exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Tracing\FWCFG
EnableFileTracing = 0

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Tracing\FWCFG
EnableConsoleTracing = 0

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Tracing\FWCFG
FileTracingMask = ffff0000

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Tracing\FWCFG
ConsoleTracingMask = ffff0000

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Tracing\FWCFG
MaxFileSize = 00100000

It modifies the following registry key(s)/entry(ies) as part of its installation routine:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Netlogon\Private
SocketAddressList = {Blank}

(Note: The default value data of the said registry entry is {User Defined}.)

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

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Tcpip\Parameters\
DNSRegisteredAdapters\{20A5AFB8-0B46-48F8-B005-BF2A8A82574A}

It creates the following registry entry(ies) to bypass Windows Firewall:

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

NOTES:

This Trojan generates random domains and connects to generated domains on TCP ports 3128 and 6667 to send and receive information.

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 9.346.05
FIRST VSAPI PATTERN DATE: 24 Aug 2012

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

Terminate a malware/grayware process

[ Learn More ]

*Note: If the detected process is not displayed in theWindows Task Manager, continue doing the next steps.

    DATA_GENERIC
  • Select the process then press the End Process button.
  • To check if the malware/grayware process/es has/have been terminated, close Windows Task Manager then open it again.
  • Close Windows Task Manager.

    • 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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
      • engel = "%Application Data%\updates\updates.exe"
    • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
      • DHCP = "1942370"
    • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
      • DNS
    • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Associations
      • LowRiskFileTypes = ".exe"
    • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Tracing\FWCFG
      • EnableFileTracing = 0
    • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Tracing\FWCFG
      • EnableConsoleTracing = 0
    • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Tracing\FWCFG
      • FileTracingMask = ffff0000
    • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Tracing\FWCFG
      • ConsoleTracingMask = ffff0000
    • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Tracing\FWCFG
      • MaxFileSize = 00100000
    • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
      • EnableFirewall = 0

    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\Tcpip\Parameters\DNSRegisteredAdapters
      • {20A5AFB8-0B46-48F8-B005-BF2A8A82574A}

    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\SYSTEM\CurrentControlSet\Services\Netlogon\Private
      • From: SocketAddressList = {Blank}
        To: SocketAddressList = {User Defined}

    Step 6

    Search and delete these folders

    [ Learn More ]
    Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
    • %Application Data%\updates

    Step 7

    Scan your computer with your Trend Micro product to delete files detected as TROJ_INJECTO.AJM. 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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