RANSOM_LOCKY.FU
Ransom:Win32/Locky.A (Microsoft), Trojan-Ransom.Win32.Locky.aex (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 deletes the initially executed copy of itself.
TECHNICAL DETAILS
195,886 bytes
EXE
No
03 Jun 2016
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.
Other System Modifications
This Trojan modifies the following file(s):
- It encrypts files and appends the extension .locky
It modifies the following registry entries:
HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = "%Desktop%\_HELP_instructions.bmp"
HKEY_CURRENT_USER\Control Panel\Desktop
WallpaperStyle = "0"
(Note: The default value data of the said registry entry is 2.)
HKEY_CURRENT_USER\Control Panel\Desktop
TileWallpaper = "0"
(Note: The default value data of the said registry entry is 0.)
Dropping Routine
This Trojan drops the following files:
- %Desktop%\_HELP_instructions.html
- %Desktop%\_HELP_instructions.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 Details
This Trojan connects to the following possibly malicious URL:
- http://{BLOCKED}.{BLOCKED}.69.90/upload/_dispatch.php
- http://{BLOCKED}.{BLOCKED}.123.60/upload/_dispatch.php
- {pseudorandom domain}.{ru, info, biz, work, pl ,org, pw, xyz, click, su}
It deletes the initially executed copy of itself
SOLUTION
9.800
12.560.06
31 May 2016
12.561.00
01 Jun 2016
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
Search and delete these components
- %Desktop%\_HELP_instructions.html
- %Desktop%\_HELP_instructions.bmp
Step 3
Scan your computer with your Trend Micro product to delete files detected as RANSOM_LOCKY.FU. 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 4
Reset your Desktop properties
Step 5
Restore encrypted files from backup.
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