TROJ_CRILOCK.YNB

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It modifies the Internet Explorer Zone Settings.

Arrival Details

This Trojan arrives as an attachment to email messages spammed by other malware/grayware or malicious users.

It 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 a copy of itself in the following folders using different file names:

• %Windows%\{random value}.exe

(Note: %Windows% is the Windows folder, which is usually C:\Windows.)

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
{random characters} = "%Windows%\{random characters}.exe"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Bit Torrent Application\
Configuration

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Bit Torrent Application\
Configuration
01000000 = "{random values}"

HKEY_CURRENT_USER\Software\Bit Torrent Application\
Configuration
02000000 = "{random values}"

HKEY_CURRENT_USER\Software\Bit Torrent Application\
Configuration
03000000 = "{random values}"

HKEY_CURRENT_USER\Software\Bit Torrent Application\
Configuration
00000000 = "{random values}"

Web Browser Home Page and Search Page Modification

This Trojan modifies the Internet Explorer Zone Settings.

NOTES:

This Trojan may connect to the URL http://{BLOCKED}cription/gate.php to download the key used in encrypting the files.

The .eml file where the malware may arrive contains the following links where the malware can be downloaded:

• http://{BLOCKED}st.org/eparcel/service.php?id=85925730
• http://{BLOCKED}st.org/eparcel/service.php?id=25189924
• http://{BLOCKED}st.org/unsubscrube.php?id=33321132

The URLs above are inaccessible as of this writing.

It connects to localhost to check Internet connection.