JS.Downloader (Symantec)
Fileless
Windows
This malware is involved in the filelessly-installed backdoor malware attack discovered early August 2017. It is able to install a backdoor malware onto the systems it infects. The malware is also downloaded via an autostart registry entry. Users affected by this malware may find their systems exhibiting malicious routines.
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 does not have any propagation routine.
It does not have any backdoor routine.
It executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.
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.
It may be downloaded from the following remote sites:
This malware arrives via the following means:
Propagation
This Trojan does not have any propagation routine.
Backdoor Routine
This Trojan does not have any backdoor routine.
Rootkit Capabilities
This Trojan does not have rootkit capabilities.
Download Routine
This Trojan connects to the following website(s) to download and execute a malicious file:
It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.
Other Details
This Trojan does the following:
It does not exploit any vulnerability.
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
Restart in Safe Mode
Step 4
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.
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as JS_POWMET.DE. 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.