1. /
  2. Security Response/
  3. Trojan.Cryptolocker.G


Risk Level 1: Very Low

July 16, 2014
August 1, 2014 1:03:21 PM
Also Known As:
Trojan-Ransom.Win32.Onion [Kaspersky], Win32/Critroni.A [Microsoft], TROJ_CRYPCTB.A [Trend]
Systems Affected:
Windows 2000, Windows 7, Windows 95, Windows 98, Windows Me, Windows NT, Windows Server 2003, Windows Server 2008, Windows Vista, Windows XP
Trojan.Cryptolocker.G is a Trojan horse that encrypts files on the compromised computer and then prompts the user to purchase a password in order to decrypt them.

Antivirus Protection Dates

  • Initial Rapid Release version July 16, 2014 revision 006
  • Latest Rapid Release version March 13, 2015 revision 006
  • Initial Daily Certified version July 16, 2014 revision 016
  • Latest Daily Certified version March 17, 2015 revision 001
  • Initial Weekly Certified release date July 16, 2014
Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Threat Assessment


  • Wild Level: Low
  • Number of Infections: 0 - 49
  • Number of Sites: 0 - 2
  • Geographical Distribution: Low
  • Threat Containment: Easy
  • Removal: Easy


  • Damage Level: Medium
  • Payload: Demands a ransom to decrypt files on the compromised computer.
  • Modifies Files: Encrypts files on the compromised computer.


  • Distribution Level: Low
Note: On May 14, 2015, modifications will be made to the threat write-ups to streamline the content. The Threat Assessment section will no longer be published as this section is no longer relevant to today's threat landscape. The Risk Level will continue to be the main threat risk assessment indicator.
Writeup By: Mark Anthony Balanza

Search Threats

Search by name
Example: W32.Beagle.AG@mm
STAR Antimalware Protection Technologies
Internet Security Threat Report