RANSOM_HIDDENTEAROFFLINE.A
Ransom.HiddenTear.Generic (Malwarebytes); Ransom:MSIL/Ryzerlo.A (Microsoft); Ransom.HiddenTear!g1 (Symantec)
Windows
Threat Type: Ransomware
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
This Ransomware arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It encrypts files with specific file extensions. It encrypts files found in specific folders. It drops files as ransom note.
TECHNICAL DETAILS
Arrival Details
This Ransomware 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 Ransomware drops the following copies of itself into the affected system and executes them:
- %User Profile%\table.exe
(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.)
It drops the following files:
- %User Profile%\winsys.txt -> contains encryption key (deleted afterwards)
- {Executed Malware Folder}\adobe.txt -> {computer name}-{user name}-{encryption key}
(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.)
Ransomware Routine
This Ransomware encrypts files with the following extensions:
- .txt
- .doc
- .docx
- .xls
- .xlsx
- .ppt
- .pptx
- .odt
- .jpg
- .png
- .csv
- .sql
- .mdb
- .sln
- .php
- .asp
- .aspx
- .html
- .xml
- .psd
It encrypts files found in the following folders:
- %Desktop%
(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.)
It appends the following extension to the file name of the encrypted files:
- .locked
It drops the following file(s) as ransom note:
- %Desktop%\READ_IT.txt
(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.)
It leaves text files that serve as ransom notes containing the following text:
- Files has been encrypted
Send me some of your salary in bitcoins or you will lose your file
Cheers, is not end of the world
SOLUTION
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
Search and delete these files
- %User Profile%\winsys.txt
- {Executed Malware Folder}\adobe.txt
- %Desktop%\READ_IT.txt
Step 4
Scan your computer with your Trend Micro product to delete files detected as RANSOM_HIDDENTEAROFFLINE.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 the following Trend Micro Support pages for more information:
Step 5
Restore encrypted files from backup.
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