ALIASES:

Trojan.Gen.2 (Symantec); Trojan-Downloader.Win32.Injecter.jmy (Kaspersky)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • 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.

  TECHNICAL DETAILS

File Size: 157,184 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 27 Mar 2015

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 creates the following folders:

  • %User Profile%\Application Data\awfouhgmuloaujqaeeph

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} 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
hrgwvphocarhsjf = "%User Profile%\awfouhgmuloaujqaeeph\hidfxjr.exe"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\AXSPH

It adds the following registry entries:

HKEY_CURRENT_USER\Software\AXSPH
serv2 = "{random characters}"

HKEY_CURRENT_USER\Software\AXSPH
serv1 = "{random characters}"

HKEY_CURRENT_USER\Software\AXSPH
inf = "{random characters}"

HKEY_CURRENT_USER\Software\AXSPH
cf1 = "338350350346292281281283289289280289282280291290280283289288281339344334335354280346338346"

HKEY_CURRENT_USER\Software\AXSPH
cf2 = "338350350346292281281283289289280289282280291291280284284282281339344334335354280346338346"

HKEY_CURRENT_USER\Software\AXSPH
lx = "345341"

HKEY_CURRENT_USER\Software\AXSPH
pr = "283"

HKEY_CURRENT_USER\Software\AXSPH
au = "283"

HKEY_CURRENT_USER\Software\AXSPH
lug1 = "{random characters}"

HKEY_CURRENT_USER\Software\AXSPH
lug2 = "{random characters}"

HKEY_CURRENT_USER\Software\AXSPH
lug4 = "{random characters}"

HKEY_CURRENT_USER\Software\AXSPH
vi = "345341"

HKEY_CURRENT_USER\Software\AXSPH
pr = "345341"

HKEY_CURRENT_USER\Software\AXSPH
vp = "325320266286280282327"

Dropping Routine

This Trojan drops the following files:

  • %User Profile%\Application Data\nvcofja
  • %User Profile%\awfouhgmuloaujqaeeph\exscn
  • %User Profile%\awfouhgmuloaujqaeeph\tdunda
  • %User Profile%\awfouhgmuloaujqaeeph\hidfxjr
  • %User Profile%\awfouhgmuloaujqaeeph\cplqyavg
  • %User Profile%\awfouhgmuloaujqaeeph\hidfxjr.exe

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

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://{BLOCKED}.98.242/system/cab/arqb.cab
  • http://{BLOCKED}.98.242/system/cab/arqa.cab
  • http://{BLOCKED}.98.242/system/pdf/st3.pdf
  • http://{BLOCKED}.98.242/system/cab/arqc.cab
  • {BLOCKED}0.1

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.750

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

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_CURRENT_USER\Software
    • AXSPH

Step 4

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
    • hrgwvphocarhsjf = "%User Profile%\awfouhgmuloaujqaeeph\hidfxjr.exe"
  • In HKEY_CURRENT_USER\Software\AXSPH
    • serv2 = "{random characters}"
  • In HKEY_CURRENT_USER\Software\AXSPH
    • serv1 = "{random characters}"
  • In HKEY_CURRENT_USER\Software\AXSPH
    • inf = "{random characters}"
  • In HKEY_CURRENT_USER\Software\AXSPH
    • cf1 = "338350350346292281281283289289280289282280291290280283289288281339344334335354280346338346"
  • In HKEY_CURRENT_USER\Software\AXSPH
    • cf2 = "338350350346292281281283289289280289282280291291280284284282281339344334335354280346338346"
  • In HKEY_CURRENT_USER\Software\AXSPH
    • lx = "345341"
  • In HKEY_CURRENT_USER\Software\AXSPH
    • pr = "283"
  • In HKEY_CURRENT_USER\Software\AXSPH
    • au = "283"
  • In HKEY_CURRENT_USER\Software\AXSPH
    • lug1 = "{random characters}"
  • In HKEY_CURRENT_USER\Software\AXSPH
    • lug2 = "{random characters}"
  • In HKEY_CURRENT_USER\Software\AXSPH
    • lug4 = "{random characters}"
  • In HKEY_CURRENT_USER\Software\AXSPH
    • vi = "345341"
  • In HKEY_CURRENT_USER\Software\AXSPH
    • pr = "345341"
  • In HKEY_CURRENT_USER\Software\AXSPH
    • vp = "325320266286280282327"

Step 5

Search and delete these components

[ Learn More ]
There may be some components that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %User Profile%\Application Data\nvcofja
  • %User Profile%\awfouhgmuloaujqaeeph\exscn
  • %User Profile%\awfouhgmuloaujqaeeph\tdunda
  • %User Profile%\awfouhgmuloaujqaeeph\hidfxjr
  • %User Profile%\awfouhgmuloaujqaeeph\cplqyavg
  • %User Profile%\awfouhgmuloaujqaeeph\hidfxjr.exe

Step 6

Search and delete this folder

[ 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.
  • %User Profile%\Application Data\awfouhgmuloaujqaeeph

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_DLOADER.YMNGH. 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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