RANSOM_CRYPTESLA.CBQ163N
Trojan.Cryptolocker.N (Symantec); Ransom:Win32/Tescrypt (Microsoft); Trojan-Ransom.Win32.Agent.ino (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
372,736 bytes
EXE
23 Mar 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.
Installation
This Trojan drops the following copies of itself into the affected system and executes them:
- %My Documents%\{random filename}.exe
(Note: %My Documents% is usually C:\Documents and Settings\{user name}\My Documents on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\Documents on Windows Vista and 7.)
It drops the following file(s)/component(s):
- %Desktop%\+-HELP-RECOVER-+{random letters}-+.html
- %Desktop%\+-HELP-RECOVER-+{random letters}-+.png
- %Desktop%\+-HELP-RECOVER-+{random letters}-+.txt
- {folders containing encrypted files}\+-HELP-RECOVER-+{random letters}-+.html
- {folders containing encrypted files}\+-HELP-RECOVER-+{random letters}-+.txt
- {folders containing encrypted files}\+-HELP-RECOVER-+{random letters}-+.png
- %My Documents%\+recover+file.txt
(Note: %My Documents% is usually C:\Documents and Settings\{user name}\My Documents on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\Documents on Windows Vista and 7.)
(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.)
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
+++{random characters} = %System%\cmd /C start " " "%My Documents%\{random filename}.exe"
Other System Modifications
This Trojan adds the following registry entries:
HKEY_CURRENT_USER\Software\trueimg
ID = "{ID}"
HKEY_CURRENT_USER\Software\{ID}
data = "{random values}"
It adds the following registry keys as part of its installation routine:
HKEY_CURRENT_USER\Software\trueimg
HKEY_CURRENT_USER\Software\{ID}
HKU\.DEFAULT\Software\
trueimg
Other Details
This Trojan connects to the following possibly malicious URL:
- http://{BLOCKED}ia.com/sysstr.php
- http://{BLOCKED}2k15.in/sysstr.php
- http://{BLOCKED}y.org/sysstr.php
- http://{BLOCKED}l.com/sysstr.php
- http://{BLOCKED}sports.info/sysstr.php
- http://{BLOCKED}legue.com/sysstr.php
It is capable of encrypting files in the affected system.