Analysis by: Erika Bianca Mendoza

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This malware is dropped by TROJ_ADOBFP.SMA.

It checks if proxy is enabled on the affected system by checking certain registry entries.

It connects to certain malicious servers and URLs, and waits for commands from a remote malicious user.

It retrieves specific information from the affected system.

This backdoor may be downloaded by other malware/grayware/spyware from remote sites. It may be dropped by other malware.

  TECHNICAL DETAILS

File Size: 23,552 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 30 Mar 2011
Payload: Connects to URLs/Ips

Arrival Details

This backdoor may be downloaded by other malware/grayware/spyware from remote sites.

It may be dropped by the following malware:

  • TROJ_ADOBFP.SMA

Backdoor Routine

This backdoor connects to the following URL(s) to send and receive commands from a remote malicious user:

  • {BLOCKED}2.{BLOCKED}3.82.99

NOTES:

Information Theft

This backdoor retrieves the following information from the affected system:

  • user name
  • host name
  • IP address
  • Windows version

Other Details
This malware checks if proxy is enabled by checking the following registry entries:

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings
ProxyServer

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Windows\CurrentVersion\Internet Settings
Proxyenable

It attempts to connect to a remote server through HTTP GET:
  • {BLOCKED}2.{BLOCKED}3.82.99\AES{random}O{encrypted data}.jsp?{encrypted data}
It may also connect to the server as:
  • {BLOCKED}2.{BLOCKED}3.82.99\SUS{random}O{random}.jsp?{encrypted data}
  • {BLOCKED}2.{BLOCKED}3.82.99\SEU{random}O{random}.jsp?{encrypted data}
  • {BLOCKED}2.{BLOCKED}3.82.99\ZES{random}O{random}.jsp?{encrypted data}
  • {BLOCKED}2.{BLOCKED}3.82.99\PES{random}O{random}.jsp?{encrypted data}
Once a connection to the server is established, it waits for the following commands:
  • exit (terminate)
  • put (download file)
  • sleep
  • dos (execute specified command)
  • run (create process)

  SOLUTION

Minimum Scan Engine: 8.900
FIRST VSAPI PATTERN FILE: 7.876.11
FIRST VSAPI PATTERN DATE: 05 Mar 2011
VSAPI OPR PATTERN File: 7.925.00
VSAPI OPR PATTERN Date: 25 Mar 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

Terminate a process file/s detected as BKDR_DEMTRAN.SM

[ Learn More ]

*Note: If the detected file/s is/are not displayed in theWindows Task Manager, continue doing the next steps.

Step 3

Scan your computer with your Trend Micro product to delete files detected as BKDR_DEMTRAN.SM. 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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