| Fullname: | Hidden Tear |
| Technical Name: | Ransom.MSIL.Tear |
| Classification: | Trojan horse |
| Type: | Ransomware |
| Subtype: | Cryptovirus |
| Origin: | Istanbul, Turkey |
| Author: | Utku Sen |
| Os: | Microsoft Windows |
| Language: | C# |
Hidden Tear is the first open-source ransomware trojan that targets computers running Microsoft Windows[1] The original sample was posted in August 2015 to GitHub.[2]
When Hidden Tear is activated, it encrypts certain types of files using a symmetric AES algorithm, then sends the symmetric key to the malware's control servers.[3] However, as Utku Sen claimed "All my malware codes are backdoored on purpose", Hidden Tear has an encryption backdoor, thus allowing him to crack various samples.[4]