Analysis by: Christopher Daniel So
 PLATFORM:

Windows 2000, XP, Server 2003

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

  • Threat Type: Backdoor

  • Destructiveness: Yes

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This backdoor has the capability to create its own server component.

  TECHNICAL DETAILS

File Size: 253,952 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 17 Sep 2010
Payload: Compromises system security

Autostart Technique

This backdoor 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\ssms
Type = 272

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

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

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\ssms
ImagePath = "{malware path and file name} -run"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\ssms
DisplayName = "System Security Manager Service"

Backdoor Routine

This backdoor has the capability to create its own server component.

It opens the following port(s) where it listens for remote commands:

  • TCP port 138

  SOLUTION

Minimum Scan Engine: 8.900

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

Identify and terminate files detected as BKDR_ESSEMS.SZP

[ Learn More ]
  1. 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.
  2. 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 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\SYSTEM\CurrentControlSet\Services
    • ssms

Step 4

Scan your computer with your Trend Micro product to delete files detected as BKDR_ESSEMS.SZP. 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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