RANSOM_CRYPMAME.A
Trojan.Cryptolocker.N (Symantec), a variant of MSIL/Filecoder.AV trojan (ESET), MSIL/Filecoder.AV!tr (Fortinet)
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
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.
TECHNICAL DETAILS
25,600 bytes
No
14 May 2016
Displays graphics/image, Encrypts files, Connects to URLs/IPs, Steals information
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 component file(s):
- %Desktop%\READ_IT.txt - ransom note
- {malware path}\WindowsUpdate.bat - used to delete the ransomware sample. This component is also deleted after execution
(Note: %Desktop% is the desktop folder, where it usually is C:\Documents and Settings\{user name}\Desktop in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\Desktop in 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 changes the desktop wallpaper by modifying the following registry entries:
HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = "%User Profile%\ransom.jpg"
It sets the system's desktop wallpaper to the following image:
Download Routine
This Trojan accesses the following websites to download files:
- http://i.imgur.com/{BLOCKED}d.jpg
- http://{BLOCKED}.{BLOCKED}.199.83/Decrypter.exe
It saves the files it downloads using the following names:
- %User Profile%\ransom.jpg - image used as wallpaper
- %User Profile%\Decrypter.exe - decryption tool
(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 encrypts files with the following extensions:
- .txt
- .doc
- .docx
- .xls
- .xlsx
- .pps
- .ppt
- .pptx
- .odt
- .gif
- .jpg
- .png
- .db
- .csv
- .sql
- .mdb
- .sln
- .php
- .asp
- .aspx
- .html
- .xml
- .psd
- .frm
- .myd
- .myi
- .dbf
- .mp3
- .mp4
- .avi
- .mov
- .mpg
- .rm
- .wmv
- .m4a
- .mpa
- .wav
- .sav
- .gam
- .log
- .ged
- .msg
- .myo
- .tax
- .ynab
- .ifx
- .ofx
- .qfx
- .qif
- .qdf
- .tax2013
- .tax2014
- .tax2015
- .box
- .ncf
- .nsf
- .ntf
- .lwp
It does the following:
- It appends the extension .locked to the encrypted files
- It avoids encrypting the following files:
- ransom.jpg
- READ_IT.txt
- It gathers the following system information and reports them to its server via HTTP POST:
- username
- pcname
- servkey
- stackTrace
- aesencrypted (encrypted password)
It sends the gathered system information to the following servers:
- http://{BLOCKED}.{BLOCKED}.199.175/createkeys.php
- http://{BLOCKED}.{BLOCKED}.199.175/getamount.php
- http://23.227.199.175/savekey.php
- http://{BLOCKED}.{BLOCKED}.199.175/update.php
- http://{BLOCKED}.{BLOCKED}.199.175/finished.php
- http://{BLOCKED}.{BLOCKED}.199.175/exception.php
- It encrypts drives C:\ to K:\
- It retrieves the bitcoin (BTC) amount to be paid by user from the server:
- http://{BLOCKED}.{BLOCKED}.199.175/getamount.php
NOTES:
The dropped ransom note READ_IT.txt contains the following message:
SOLUTION
9.800
12.526.08
14 May 2016
12.527.00
15 May 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
Identify and terminate files detected as RANSOM_CRYPMAME.A
- 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.
- 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.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
Step 4
Search and delete these files
- %Desktop%\READ_IT.txt
- {malware path}\WindowsUpdate.bat
- %User Profile%\ransom.jpg
Step 5
Scan your computer with your Trend Micro product to delete files detected as RANSOM_CRYPMAME.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
Reset your Desktop properties
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