Analysis by: Pearl Charlaine Espejo
ALIASES:

Trojan.Rovnix (Malwarebytes); TrojanDropper:Win32/Rovnix.P (Microsoft); W32/ROVNIX.YPOE!tr (Fortinet); Trojan.Win32.Rovnix.AB (Baidu-International)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

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

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.

It does not have any propagation routine.

It does not have any backdoor routine.

It modifies the Internet Explorer Zone Settings.

It connects to certain websites to send and receive information. However, as of this writing, the said sites are inaccessible. It deletes the initially executed copy of itself. It gathers information and reports it to its servers.

  TECHNICAL DETAILS

File Size: 453,482 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 25 Dec 2015
Payload: Steals information, Downloads files

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 drops the following file(s)/component(s):

  • %User Temp%\L{Volume ID}
  • %User Temp%\NTFS.sys
  • %User Temp%\tmp{random characters}.tmp
  • %System%\BOOT.dat

(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.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

It drops the following copies of itself into the affected system:

  • %Application Data%\BackUp{Volume ID}.exe

(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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 mutexes to ensure that only one of its copies runs at any one time:

  • "Global\INSNTFS{Volume ID}"
  • "Global\UACNTFS{Volume ID}"
  • "Global\BDNTFS{Volume ID}"

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
BackUp{Volume ID} = "%Application Data%\BackUp{Volume ID}.exe"

It adds and runs the following services:

  • Service Name: BS{Volume ID}
    Display Name: BS{Volume ID}
    Start Type: SERVICE_DEMAND_START
    Binary Pathname: %User Temp%\NTFS.sys

(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 System Modifications

This Trojan adds the following registry entries:

HKEY_CURRENT_USER\Software\Sysinternals\
C
EulaAccepted = 1

HKEY_CURRENT_USER\Software\Microsoft\
Installer\Products\B{Volume ID}
LP = "%User temp%\L{Volume ID}"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
RSA{Volume ID} = "%System%\rundll32.exe "%Application Data%\Microsoft\Crypto\RSA\RSA{Volume ID}.dll",DllInitialize"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Disk Defragmenter = "%System%\rundll32.exe "%Application Data%\defragsvc.dll",DllInitialize"

HKEY_CURRENT_USER\Software\Microsoft\
Installer\Products\B{Volume ID}
ID = "-- default --"

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Process Termination

This Trojan terminates the following processes if found running in the affected system's memory:

  • iexplore.exe

Web Browser Home Page and Search Page Modification

This Trojan modifies the Internet Explorer Zone Settings.

Other Details

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

  • http://{BLOCKED}erfliremsnk.net/cgi-bin/150915/post.cgi

It checks for the presence of the following process(es):

  • explorer.exe

It does the following:

  • It modifies the NTFS boot sector to load its encrypted code
  • Terminates itself if Hard Disk is Protected and/or Encrypted by any of the following:
    • BitLocker
    • VeraCrypt
    • TrueCrypt
  • Can Log off Current User
  • Deletes the files inside %User Temp% folder
  • Terminates itself if the malware name and/or path has the following substrings:
    • samp
    • smpl
    • vir
    • malw
    • test
    • troj

(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.)

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

It deletes the initially executed copy of itself

It terminates itself if any of the following user name(s) are found in the affected system:

  • luser
  • perl
  • python
  • trace
  • dump

It gathers the following information and reports it to its servers:

  • Malware ID
  • Filepath and Name of the log file
  • OS Version and Architecture
  • File System
  • Volume ID
  • System Date and Time
  • Child Process ID
  • Child Filepath and Filename
  • Parent Process ID
  • Parent Filepath and Filename
  • Current Malware Directory
  • Username
  • SID SubAuthority Level

NOTES:

This malware checks for the following to see if it is running in virtual environment:

  • VMSwitchUserControlClass - window name for VMWare
  • HKEY_LOCAL_MACHINE\HARDWARE\ACPI\DSDT\PRLS__\PRLSACPI - registry key for Parallels Workstation
  • CPUID - to compare the result to that of the Parallels Workstation

It does not continue if it detects that is running in a virtual environment.

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 12.258.04
FIRST VSAPI PATTERN DATE: 07 Jan 2016
VSAPI OPR PATTERN File: 12.259.00
VSAPI OPR PATTERN Date: 08 Jan 2016

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

Restart in Safe Mode

[ Learn More ]

Step 4

Disable this malware service

[ Learn More ]
  • BS{Volume ID}

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • BackUp{Volume ID} = "%Application Data%\BackUp{Volume ID}.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • RSA{Volume ID} = "%System%\rundll32.exe "%Application Data%\Microsoft\Crypto\RSA\RSA{Volume ID}.dll",DllInitialize
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • Disk Defragmenter = "%System%\rundll32.exe "%Application Data%\defragsvc.dll",DllInitialize"
  • In HKEY_CURRENT_USER\Software\Microsoft\Installer\Products\B{Volume ID}
    • LP = "%User Temp%\L{Volume ID}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Installer\Products\B{Volume ID}
    • ID = "-- default --"
  • In HKEY_CURRENT_USER\Software\Sysinternals\C
    • EulaAccepted = 1

Step 6

Search and delete these files

[ Learn More ]
There may be some files 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 Temp%\L{Volume ID}
  • %User Temp%\NTFS.sys
  • %User Temp%\tmp{random characters}.tmp
  • %System%\BOOT.dat

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_ROVNIX.I. 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 8

Reset Internet security settings

[ Learn More ]

NOTES:

For Trend Micro product users, use the ATTK with ATRT to restore the modified Initial Program Loader (IPL) of an active NTFS partition.


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