Analysis by: Sammy Chua
 Modified by: RonJay Kristoffer Caragay
ALIASES:

TrojanDownloader:Win32/Rovnix.A (Microsoft); Trojan.Win32.Rovnix.fv (Kaspersky); Win32:Rovnix-N [Trj] (Avast); TR/Rovnix.Gen9 (Avira); a variant of Win32/Rovnix.AG (ESET-NOD32); W32/Rovnix.AG!tr (Fortinet); Trojan.Win32.Rovnix (Ikarus); Trojan.Rovnix (Malwarebytes)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

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

This Trojan may arrive bundled with malware packages as a malware component. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It deletes files in certain folders, disabling programs and applications from properly running.

It does not have any propagation routine.

It does not have any backdoor routine.

It connects to certain websites to send and receive information. It requires its main component to successfully perform its intended routine. However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 78,336 bytes
File Type: DLL
Memory Resident: Yes
Initial Samples Received Date: 23 Sep 2015
Payload: Connects to URLs/IPs, Downloads files

Arrival Details

This Trojan may arrive bundled with malware packages as a malware component.

It 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 adds the following processes:

  • svchost.exe

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • Global\BDNTFS{Volume Serial Number}

It injects codes into the following process(es):

  • created svchost.exe

Other System Modifications

This Trojan deletes files in the following folders:

  • %User Temp%

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

It adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Installer\Products\B{Volume Serial Number}

HKEY_CURRENT_USER\Software\Microsoft\
Installer\Products\B{Volume Serial Number}\
PLUGIN

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Installer\Products\B{Volume Serial Number}
SH1 = "{C&C server}"

HKEY_CURRENT_USER\Software\Microsoft\
Installer\Products\B{Volume Serial Number}
SH2 = "{C&C server}"

HKEY_CURRENT_USER\Software\Microsoft\
Installer\Products\B{Volume Serial Number}
SH3 = "{C&C server}"

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Download Routine

This Trojan connects to the following website(s) to download and execute a malicious file:

  • http://{domain name}/download/{random}.zip

It saves the files it downloads using the following names:

  • %User Temp%\~{random}.tmp ← deleted afterwards

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)

Other Details

This Trojan connects to the following website to send and receive information:

  • {domain name}/login.asp
  • {domain name}/images/pixel.gif
  • {domain name}/images/transparent.gif
  • {domain name}/images/logout.gif
  • {domain name}/{Volume Serial Number}32.gif

It requires its main component to successfully perform its intended routine.

It performs DNS requests to the following sites:

  • {BLOCKED}babanahujtr.org
  • {BLOCKED}ebabanahujtr2.org
  • {BLOCKED}ebabanahujtr3.org
  • {randomly generated domain}.ru
  • {randomly generated domain}.com
  • {randomly generated domain}.net
  • {randomly generated domain}.biz
  • {randomly generated domain}.cn

However, as of this writing, the said sites are inaccessible.

NOTES:
This malware check if the DNS server does not contain the following strings:

  • control
  • sink
  • hole
  • dynadot
  • block
  • malw
  • anti
  • googl
  • hack
  • trojan
  • abuse
  • virus
  • black
  • spam

It can use TOR service by accessing the following server:

  • {BLOCKED}vg6cktylw2.onion

It connects to the following NTP server:

  • 0.de.pool.ntp.org
  • 0.lu.pool.ntp.org
  • ntp1.stratum2.ru

It creates named pipe\\.\pipe\vhost{Volume Serial Number} to communicate to its main component.

It checks if its process name is any of the following:

  • winlogon.exe
  • svchost.exe
  • explorer.exe
  • rundll32.exe

If it is running in winlogon.exe it uses HKEY_LOCAL_MACHINE instead of HKEY_CURRENT_USER for its added registries.

It searches for itself in the following auto-start registry:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run

If found, it will periodically recreate its auto-start entry.

  SOLUTION

Minimum Scan Engine: 9.750
FIRST VSAPI PATTERN FILE: 11.936.04
FIRST VSAPI PATTERN DATE: 23 Sep 2015
VSAPI OPR PATTERN File: 11.937.00
VSAPI OPR PATTERN Date: 24 Sep 2015

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

Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.

Step 3

Scan your computer with your Trend Micro product and note files detected as TROJ_ROVNIX.YPOA

Step 4

Restart in Safe Mode

[ Learn More ]

Step 5

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\Microsoft\Installer\Products
    • B{random numbers}
  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Installer\Products
    • B{random numbers}

Step 6

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
    • {value name} = "{contains malware path and filename}"

Step 7

Search and delete the files detected as TROJ_ROVNIX.YPOA

*Note: Some component files may be 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.

To stop the malware/grayware from running when certain files are opened:

For Windows 2000, Windows XP, and Windows Server 2003:

  1. Right-click Start then click Search....
  2. In the File name* input box, type the name of the file that was detected earlier.
  3. In the Look In drop-down list, select My Computer then press Enter.
  4. Once located, select the file then press SHIFT+DELETE to delete it.
    *Note: The file name input box title varies depending on the Windows version (e.g. Search for files or folders named or All or part of the file name.).

For Windows Vista, Windows 7, Windows Server 2008, Windows 8, Windows 8.1, and Windows Server 2012 (R2):

  1. Open a Windows Explorer window.
    • For Windows Vista, 7, and Server 2008 users, click Start>Computer.
    • For Windows 8, 8.1, and Server 2012 users, right-click on the lower left corner of the screen,then click File Explorer.
  2. In the Search Computer/This PC input box, type the name of the file that was detected earlier.
  3. Once located, select the file then press SHIFT+DELETE to delete it.
    *Note: Read the following Microsoft page if these steps do not work on Windows 7.

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_ROVNIX.YPOA. 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 9

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