Trojan.JS.TWINFLOWER.A
Trojan-Downloader:JS/TeslaCrypt.C (FSECURE)
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
Downloaded from the Internet, Dropped by other malware
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.
It requires its main component to successfully perform its intended routine. However, as of this writing, the said sites are inaccessible.
TECHNICAL DETAILS
8,650 bytes
JS
No
27 Mar 2020
Connects to URLs/IPs, Modifies system registry
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.
Download Routine
This Trojan downloads the file from the following URL and renames the file when stored in the affected system:
- http://{BLOCKED}.{BLOCKED}.37.73:8099/ssd_cfg.db
It saves the files it downloads using the following names:
- %User Temp%\WinRAR\elements162816.db
(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
Other Details
This Trojan adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
WCCloud
cfg = {encoded value}
It requires its main component to successfully perform its intended routine.
It checks for the presence of the following process(es):
- wireshark.exe
- fiddler.exe
- httpanalyze
- HipsDaemon
- softice.exe
- windgb.exe
- dbg.exe
- tcpmon
- networktrafficview.exe
- hookme.exe
- sniff.exe
- chkencap.exe
- wsockexpert
It does the following:
- It does not perform its download routine if any of the processes are detected running in the affected system
- Connects to the following URL's:
- http://yky.{BLOCKED}e.com:38275/api/cload.asp?sid={numbers}
- https://{BLOCKED}a.{BLOCKED}1.la/go1?id=20625191&rt={numbers}&rl=1280*1024&lang=zh-CN&ct=unknow&pf=1&ins=1&vd=1&ce=1&cd=32&ds=hello&ing=1&ekc=&sid={numbers}&tt=hello&kw=hello&cu=https:\\{BLOCKED}o.{BLOCKED}u.com&pu=https:\\{BLOCKED}o.{BLOCKED}u.com
- https://{BLOCKED}a.{BLOCKED}1.la/go1?id=20625191&rt={numbers}&rl=1280*1024&lang=zh-CN&ct=unknow&pf=1&ins=1&vd=1&ce=1&cd=32&ds=hello&ing=1&ekc=&sid={numbers}&tt=hello&kw=hello&cu=https:\\www.{BLOCKED}u.com\{value}&pu=https:\\www.{BLOCKED}u.com\{value}
However, as of this writing, the said sites are inaccessible.
SOLUTION
9.850
15.780.03
02 Apr 2020
15.781.00
03 Apr 2020
Step 1
Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 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
Delete this registry value
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\WCCloud
- cfg = {encoded value}
- cfg = {encoded value}
Step 4
Scan your computer with your Trend Micro product to delete files detected as Trojan.JS.TWINFLOWER.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:
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