RANSOM_ROTORCRYPT.A
Trojan.Win32.Pakes.ausu (KASPERSKY)
Windows

Threat Type: Ransomware
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
Dropped by other malware, Downloaded from the Internet
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.
TECHNICAL DETAILS
165,377 bytes
EXE
Yes
25 May 2017
Encrypts files
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 drops the following copies of itself into the affected system:
- %AppDataLocal%\Microsoft Help\{8 random characters}.exe
(Note: %AppDataLocal% is the Application Data folder found in Local Settings, where it is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local 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.)
Autostart Technique
This Ransomware adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{8 random characters} = %Application Data%\Microsoft\{8 random characters}.exe
It drops the following shortcut pointing to its copy in the User Startup folder to enable its automatic execution at every system startup:
- {8 characters random}.lnk
Other System Modifications
This Ransomware adds the following registry keys:
HKEY_CURRENT_USER\Software\{8 random characters}
HKEY_LOCAL_MACHINE\SOFTWARE\{8 random characters}
Other Details
This Ransomware does the following:
- Executes following commands: -vssadmin.exe delete shadows /all /quiet
Ransomware Routine
This Ransomware avoids encrypting files with the following strings in their file name:
- .bat
- .com
- .cpl
- .dll
- .exe
- .ini
- .lnk
- .msc
- .msp
- .scf
- .scr
- .sys
It avoids encrypting files found in the following folders:
- %Windows%
(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)
It appends the following extension to the file name of the encrypted files:
- !______PATAGONIA5000@{BLOCKED}MAIL.COM______.rar
SOLUTION
9.850
13.428.04
25 May 2017
13.429.00
26 May 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
Restart in Safe Mode
Step 4
Delete this registry key
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 = {8 random characters}
- Software = {8 random characters}
- In HKEY_LOCAL_MACHINE
- SOFTWARE = {8 random characters}
- SOFTWARE = {8 random characters}
Step 5
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\Windows\CurrentVersion\Run
- {8 random characters} = "%Application Data%\Microsoft\{8 random characters}.exe
- {8 random characters} = "%Application Data%\Microsoft\{8 random characters}.exe
Step 6
Search and delete these files
- %User Startup%\{8 random characters}.lnk
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as RANSOM_ROTORCRYPT.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.
Step 8
Restore encrypted files from backup.
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