Ransom.Win32.NEMISIS.SM
Ransom:Win32/CryptoLemPiz.A (Microsoft); GenericRXBJ-HZ!ABCA8F0299F6 (McAfee); Troj/Ransom-EMW (Sophos); Trojan.Win32.Generic!BT (Sunbelt)
Windows
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Ransomware
Destructiveness: No
Encrypted:
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 drops files as ransom note.
TECHNICAL DETAILS
83,456 bytes
EXE
Yes
29 Oct 2019
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 adds the following processes:
- "%System%\cmd.exe" /c "vssadmin.exe delete shadows /all /quiet"
- "%System%\cmd.exe" /c "bcdedit.exe /set {default} recoveryenabled no"
- "%System%\cmd.exe" /c "bcdedit.exe /set {default} bootstatuspolicy ignoreallfailures"
- "%System%\NOTEPAD.EXE" %User Temp%\temp000000.txt
- %User Temp%\temp000000.txt
- vssadmin.exe delete shadows /all /quiet
- bcdedit.exe /set {default} recoveryenabled no
- bcdedit.exe /set {default} bootstatuspolicy ignoreallfailures
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %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).)
Dropping Routine
This Ransomware drops the following files:
- %User Temp%\1215928222
- %User Temp%\temp000000.txt
(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).)
Ransomware Routine
This Ransomware renames encrypted files using the following names:
- {encrypted file}.WECANHELP
It drops the following file(s) as ransom note:
- YIHYQML5ZUXXOGETT
- _RESTORE FILES_.txt
SOLUTION
9.850
Step 1
Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:
- Troj.Win32.TRX.XXPE50FFF032
Step 2
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 3
Identify and terminate files detected as Ransom.Win32.NEMISIS.SM
- 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 these components
- %User Temp%\1215928222
- %User Temp%\temp000000.txt
Step 5
Scan your computer with your Trend Micro product to delete files detected as Ransom.Win32.NEMISIS.SM. 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 6
Restore encrypted files from backup.
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