WORM_PHORPIEX.VTO

 Analysis by: Cris Nowell Pantanilla

 ALIASES:

Trojan.Win32.Cosmu.cxgw (Kaspersky), Trojan:Win32/Bagsu!rfn (Microsoft),

 PLATFORM:

Windows

 OVERALL RISK RATING:
 REPORTED INFECTION:

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Copies itself in all available logical drives, Propagates via removable drives


This worm arrives via removable drives.

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

  TECHNICAL DETAILS

File Size:

903,168 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

11 Oct 2016

Payload:

Connects to URLs/IPs, Downloads files

Arrival Details

This worm arrives via removable drives.

Installation

This worm drops the following copies of itself into the affected system:

  • %WINDOWS%\M-50504528343485849294856957580535350\winmgr.exe

It creates the following folders:

  • %WINDOWS%\M-50504528343485849294856957580535350

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Microsoft Windows Manager = "%WINDOWS%\M-50504528343485849294856957580535350\winmgr.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Microsoft Windows Manager = "%WINDOWS%\M-50504528343485849294856957580535350\winmgr.exe"

Other System Modifications

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

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%WINDOWS%\M-50504528343485849294856957580535350\winmgr.exe = "%WINDOWS%\M-50504528343485849294856957580535350\winmgr.exe:*:Enabled:Microsoft Windows Manager"

Propagation

This worm drops the following copy(ies) of itself in all removable drives:

  • Private.exe
  • Movies.exe
  • Pictures.exe
  • Secret.exe
  • Documents.exe
  • Music.exe
  • winmgr.exe
  • 505040.exe
  • Porn.exe

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

The said .INF file contains the following strings:

{garbage strings}
[autorun]
{garbage strings}
icon=%SystemRoot%\system32\SHELL32.dll,4
{garbage strings}
action=Open folder to view files
{garbage strings}
shellexecute=windrv.exe
{garbage strings}
UseAutoPlay=1
{garbage strings}

Backdoor Routine

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

  • {BLOCKED}aus.ru
  • {BLOCKED}000.ru
  • {BLOCKED}100.ru
  • {BLOCKED}200.ru
  • {BLOCKED}300.ru
  • {BLOCKED}400.ru

As of this writing, the said servers are currently inaccessible.

Other Details

This worm connects to the following URL(s) to get the affected system's IP address:

  • http://api.wipmania.com/

It does the following:

  • Checks presence of the following to see if its running in a virtual machine:
    • qemu
    • virtual
    • vmware
    • SbieDllX.dll
    • SbieDll.dll
  • Other System Modification
    • It drops copies of itself in all logical drives. It then use the names of the folders located on the said drives as filenames of Shortcut files that points to the copy of the malware. It then hides the original folders to trick users on opening the shortcut files.
  • It is capable of downloading and executing files on the affected system.

  SOLUTION

Minimum Scan Engine:

9.800

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

Identify and terminate files detected as WORM_PHORPIEX.VTO

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 3

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
    • Microsoft Windows Manager = "%WINDOWS%\M-50504528343485849294856957580535350\winmgr.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • Microsoft Windows Manager = "%WINDOWS%\M-50504528343485849294856957580535350\winmgr.exe"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • %WINDOWS%\M-50504528343485849294856957580535350\winmgr.exe = "%WINDOWS%\M-50504528343485849294856957580535350\winmgr.exe:*:Enabled:Microsoft Windows Manager"

Step 4

Search and delete these folders

[ 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. %WINDOWS%\M-50504528343485849294856957580535350

Step 5

Search and delete AUTORUN.INF files created by WORM_PHORPIEX.VTO that contain these strings

[ Learn More ]

{garbage strings} [autorun] {garbage strings} icon=%SystemRoot%\system32\SHELL32.dll,4 {garbage strings} action=Open folder to view files {garbage strings} shellexecute=windrv.exe {garbage strings} UseAutoPlay=1 {garbage strings}

Step 6

Scan your computer with your Trend Micro product to delete files detected as WORM_PHORPIEX.VTO. 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 7

  1. Open a command prompt.
    • For Windows 2000, Windows XP, and Windows Server 2003 users, click Start>Run. In the Search box, type CMD then press Enter.
    • For Windows Vista, Windows 7, and Windows Server 2008 users, click Start, type CMD in the Search input field then press Enter.
    • For Windows 8, Windows 8.1, and Windows Server 2012 users, right-click on the lower-left corner of the screen, click Command Prompt.
  2. In the CMD console, type the following:

    ATTRIB [+R | -R] [+A | -A ] [+S | -S] [+H | -H] [+I | -I] [drive:][path][file name] [/S [/D] [/L]]

    Where:
    + Sets an attribute.
    - Clears an attribute
    R Read-only file attribute
    A Archive file attribute
    S System file attribute
    H Hidden file attribute
    I Not content indexed file attribute
    [drive:][path][filename]
    Specifies a file or files for attrib to process
    /S Processes matching files in the current folder and all subfolders.
    /D Processes folders
    /L Work on the attributes of the Symbolic Link versus the target of the Symbolic Link
    Example:
    To unhide all files and folders (including subfolders) in drive D:
    ATTRIB –H D:\* /S /D
  3. Repeat Step 3 for folders and files in other drives or folders.


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