RANSOM_LOCKY.HAR
Ransom:Win32/Locky.A (Microsoft), Trojan-Ransom.Win32.Locky.vjh (Kaspersky)
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
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 is capable of encrypting files in the affected system.
TECHNICAL DETAILS
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.
Installation
This Trojan drops the following files:
- {folder of encrypted files}\_{number of folders encrypted}_WHAT_is.html
It drops and executes the following files:
- %Desktop%\_WHAT_is.html
- %Desktop%\_WHAT_is.bmp
(Note: %Desktop% is the desktop folder, where it usually is C:\Documents and Settings\{user name}\Desktop in Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\Desktop in 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.)
Other System Modifications
This Trojan adds the following registry entries as part of its installation routine:
HKEY_CURRENT_USER\Control Panel\Desktop
TileWallpaper = "0"
(Note: The default value data of the said registry entry is {user preference}.)
HKEY_CURRENT_USER\Control Panel\Desktop
WallpaperStyle = "0"
(Note: The default value data of the said registry entry is {user preference}.)
HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = "%Desktop%\_WHAT_is.bmp"
(Note: The default value data of the said registry entry is {user preference}.)
Other Details
This Trojan connects to the following possibly malicious URL:
- http://{BLOCKED}.{BLOCKED}.107.6/message.php
- http://{BLOCKED}.{BLOCKED}.27.222/message.php
- http://{random generated domain}.{ru, info, biz, click, su, work, pl, org, pw, xyz}/message.php
It renames encrypted files using the following names:
- {unique ID per victim}-{identifier}.thor
It is capable of encrypting files in the affected system.
SOLUTION
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
Search and delete this file
Step 5
Reset your Desktop properties
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as RANSOM_LOCKY.HAR. 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 7
Restore encrypted files from backup.
Step 8
Scan your computer with your Trend Micro product to delete files detected as RANSOM_LOCKY.HAR. 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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