RANSOM_SHUJIN.A
Trojan-Ransom.Win32.Agent.iop (Kaspersky), Win32/Filecoder.Shujin.A trojan (ESET)
Windows
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
This ransomware attempts to bait Chinese users by using Chinese language in its ransom notes and interface.
To get a one-glance comprehensive view of the behavior of this Trojan, refer to the Threat Diagram shown below.
![](https://documents.trendmicro.com/images/ransom_shujin_a.jpg)
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
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 files:
- %Desktop%\文件解密帮助.txt - ransom note
- %User Temp%\{8 random numnbers}.bat - used to delete the malware copy. 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.. %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.)
NOTES:
This malware deletes itself after execution.
It displays the following window showing the total number of encrypted files and total size of encrypted files:
![](http://documents.trendmicro.com/images/RANSOM_SHUJIN_A1.jpg)
The dropped ransom note contains the instruction to download the Tor browser to connect to the attacker's website:
![](http://documents.trendmicro.com/images/RANSOM_SHUJIN_A22.jpg)
Below are screenshots of the attacker's main website:
![](http://documents.trendmicro.com/images/RANSOM_SHUJIN_A33.jpg)
![](http://documents.trendmicro.com/images/RANSOM_SHUJIN_A44.jpg)
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
Identify and terminate files detected as RANSOM_SHUJIN.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 the file detected as RANSOM_SHUJIN.A
Step 5
Search and delete these files
- %Desktop%\文件解密帮助.txt
Step 6
Scan your computer with your Trend Micro product to delete files detected as RANSOM_SHUJIN.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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