This malware may arrive as an infected Word or Excel document. It uses Windows PowerShell to carry out its malicious routines.
To get a one-glance comprehensive view of the behavior of this Backdoor, refer to the Threat Diagram shown below.
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.
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.
Installation
This backdoor creates the following folders:
Autostart Technique
This backdoor adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{GUID} = "wscript.exe %ApplicationData%\{GUID}\{GUID}.vbs"
Backdoor Routine
This backdoor opens the following ports:
- 8123 - Used for Web Proxy (Polipo)
- 9050 - Used for traffic encryption (TOR)
It connects to the following URL(s) to send and receive commands from a remote malicious user:
- http://{BLOCKED}jqj42hu.onion/get.php?s=setup&mom=04B69000-BC25-11E0-0000-3CD92B4C7E25&uid={GUID}
- http://{BLOCKED}jqj42hu.onion/get.php?s=setinfo&uid={GUID}
It posts the following information to its command and control (C&C) server:
- IP Address
- Country code
- Country name
- Region code
- Region name
- City
- Zipcode
- Latitude
- User account privilege
- OS version
- OS architecture
- Domain
- OS Language
- Microsoft Office applications
- Microsoft Office application versions
Download Routine
This backdoor connects to the following URL(s) to download its component file(s):
- http://i.{BLOCKED}n.de/
- http://gg.{BLOCKED}z.cc/
- http://i.{BLOCKED}n.de/
It saves the files it downloads using the following names:
- %ApplicationData%\{GUID}\{GUID}.zip - contains 'tor.exe' and 'polipo.exe'
- %ApplicationData%\{GUID}\tor.exe
- %ApplicationData%\{GUID}\polipo.exe
- %ApplicationData%\{GUID}\{GUID}.vbs - C&C generated file
Other Details
This backdoor connects to the following URL(s) to get the affected system's IP address:
- http://freegeoip.net/json/
It drops the following file(s)/component(s):
- %ApplicationData%\{GUID}\roaminglog - TOR initialization log
NOTES:
This backdoor requires the application Windows PowerShell to execute properly.
This backdoor retrieves the infection routine from the C&C server to infect files with the following extension:
- *.doc
- *.docx
- *.xls
- *.xlsx
This backdoor saves a copy of each *.docx files to *.doc format and *.xlsx files to *.xls format under the same directory and deletes the original file.
This backdoor lowers the security setting of the following applications:
- Microsoft Office Word
- Microsoft Office Excel
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
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To restart in Safe Mode:
• For Windows 2000 users
- Restart your computer.
- Press F8 when you see the Starting Windows bar at the bottom of the screen.
- Choose the Safe Mode option from the Windows Advanced Options menu then press Enter.
• For Windows XP users
- Restart your computer.
- Press F8 after the Power-On Self Test (POST) routine is done. If the Windows Advanced Options menu does not appear, try restarting then pressing F8 several times when the POST screen appears.
- Choose the Safe Mode option from the Windows Advanced Options menu then press Enter.
• For Windows Server 2003 users
- Restart your computer.
- Press F8 after Windows starts up. If the Windows Advanced Options menu does not appear, try restarting again and pressing F8 several times afterward.
- On the Windows Advanced Option menu, use the arrow keys to select Safe Mode then press Enter.
• For Windows Vista and Windows 7 users
- Restart your computer.
- Press F8 after the Power-On Self Test (POST) routine is done. If the Advanced Boot Options menu does not appear, try restarting and then pressing F8 several times after the POST screen is displayed.
- On the Advanced Boot Options menu, use the arrow keys to select the Safe Mode option, and then press Enter.
Step 3
Delete this registry value
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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
- {GUID} = "wscript.exe %ApplicationData%\{GUID}\{GUID}.vbs"
To delete the registry value this malware created:
- Open Registry Editor. To do this, click Start>Run, type regedit in the text box provided, then press Enter.
- In the left panel of the Registry Editor window, double-click the following:
HKEY_CURRENT_USER>Software>Microsoft>Windows>CurrentVersion>Run - In the right panel, locate and delete the entry:
{GUID} = "wscript.exe %ApplicationData%\{GUID}\{GUID}.vbs" - Close Registry Editor.
Step 4
Search and delete these folders
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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.
- %ApplicationData%\{GUID}\{GUID}.zip
- %ApplicationData%\{GUID}\tor.exe
- %ApplicationData%\{GUID}\polipo.exe
- %ApplicationData%\{GUID}\roaminglog
- %ApplicationData%\{GUID}\{GUID}.vbs
To delete malware/grayware/spyware folders:
- Right-click Start then click Search... or Find..., depending on the version of Windows you are running.
- In the Named input box, type:
- %ApplicationData%\{GUID}\{GUID}.zip
- %ApplicationData%\{GUID}\tor.exe
- %ApplicationData%\{GUID}\polipo.exe
- %ApplicationData%\{GUID}\roaminglog
- %ApplicationData%\{GUID}\{GUID}.vbs
- In the Look In drop-down list, select My Computer, then press Enter.
- Once located, select the folder then press SHIFT+DELETE to permanently delete the folder.
- Repeat steps 2 to 4 for the remaining folders:
- %ApplicationData%\{GUID}\{GUID}.zip
- %ApplicationData%\{GUID}\tor.exe
- %ApplicationData%\{GUID}\polipo.exe
- %ApplicationData%\{GUID}\roaminglog
- %ApplicationData%\{GUID}\{GUID}.vbs
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as X97M_CRIGENT.A. 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 6
Scan your computer with your Trend Micro product to delete files detected as X97M_CRIGENT.A. 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.
NOTES:
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