JS_NEMUCOD.ELDSAUDV
JS/TrojanDownloader.Agent.QCX (ESET-NOD32); JS/Nemucod.tn (McAfee); JS.Downloader (Symantec)
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
Dropped by other malware, Downloaded from the Internet, Spammed via email
This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites. It arrives as an attachment to email messages spammed by other malware/grayware or malicious users.
It executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system. As of this writing, the said sites are inaccessible.
TECHNICAL DETAILS
2,706 bytes
JS
No
04 Apr 2017
Connects to URLs/IPs, Downloads files, Executes files
Arrival Details
This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.
It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.
It arrives as an attachment to the following email messages spammed by other malware/grayware or malicious users:
- The malware arrives as an embedded file on a document:
Download Routine
This Trojan accesses the following websites to download files:
- http://disk.{BLOCKED}iongarden.com/js60.bin
It saves the files it downloads using the following names:
- %Application Data%\Microsoft\Windows\Templates\{random number}.exe
(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming 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.)
It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.
As of this writing, the said sites are inaccessible.
Other Details
This Trojan does the following:
- It does not proceed with its routine if the current year is not 2017.
- It queries the data of the registry entry HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\SystemRoot and uses the second character of this data for its decryption. The decryption will not work if the second character is not ":".
SOLUTION
9.850
13.318.03
04 Apr 2017
13.319.00
05 Apr 2017
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
- %Application Data%\Microsoft\Windows\Templates\{random number}.exe
Step 4
Scan your computer with your Trend Micro product to delete files detected as JS_NEMUCOD.ELDSAUDV. 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.
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