ALIASES:

Trojan-Dropper.Win32.Dorifel.aete (Kaspersky); Troj/Mdrop-FDT (Sophos)

 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: Backdoor

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel: Dropped by other malware, Downloaded from the Internet

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It listens on ports.

  TECHNICAL DETAILS

File Size: 27,648 bytes
File Type: , EXE
Memory Resident: Yes
Initial Samples Received Date: 16 Jun 2013
Payload: Connects to URLs/IPs

Arrival Details

This backdoor arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Autostart Technique

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

HKEY_LOCAL_MACHINE
SOFTWARE\Microsoft\ Windows\CurrentVersion\Run = SunJavaUpdateSched = "%All Users Profile%"\svchost.exe - (If running under VMWare Environment)

HKEY_LOCAL_MACHINE
SOFTWARE\Microsoft\ Windows\CurrentVersion\policies\ Explorer\Run = {Random Number} = "%All Users Profile%"\{Randome Filename}

Other System Modifications

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

HKEY_LOCAL_MACHINE
YSTEM\CurrentControlSet\ Services\SharedAccess\Parameters\ FirewallPolicy\StandardProfile\AuthorizedApplications\ List = {malware path and file name} = "{malware path and file name} "{malware path and file name}:*:Enabled:{File Description}""

Backdoor Routine

This backdoor listens on the following port(s):

  • 8000 (If Running Under VMWare Environment)

Other Details

This backdoor connects to the following possibly malicious URL:

  • http://www.{BLOCKED}n.ru/jiangyin.php
  • http://www.{BLOCKED}y.ru/black.php

NOTES:
The checks if the malware is running under VMWare Environment. It will perform different routine of found true.

  SOLUTION

Minimum Scan Engine: 9.300
FIRST VSAPI PATTERN FILE: 9.988.03
FIRST VSAPI PATTERN DATE: 18 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

Restart in Safe Mode

[ Learn More ]

Step 3

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


*Note: 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.

Step 4

Search and delete files detected as BKDR_ANDROM.GE

[ 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.

Step 5

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
    • SunJavaUpdateSched = "%All Users Profile%"\svchost.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\Run
    • {random number} = "%All Users Profile%"\{Random Filename}
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • {malware path and file name} = "{malware path and file name}:*:Enabled:{File Description}"

Step 6

Scan your computer with your Trend Micro product to delete files detected as BKDR_ANDROM.GE. 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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