Rifdoor is a remote access trojan (RAT) that shares numerous code similarities with HotCroissant.[1]

ID: S0433
Platforms: Windows
Version: 1.0
Created: 05 May 2020
Last Modified: 08 May 2020

Techniques Used

Domain ID Name Use
Enterprise T1547 .001 Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder

Rifdoor has created a new registry entry at HKEY_CURRENT_USERS\Software\Microsoft\Windows\CurrentVersion\Run\Graphics with a value of C:\ProgramData\Initech\Initech.exe /run.[1]

Enterprise T1573 .001 Encrypted Channel: Symmetric Cryptography

Rifdoor has encrypted command and control (C2) communications with a stream cipher.[1]

Enterprise T1027 Obfuscated Files or Information

Rifdoor has encrypted strings with a single byte XOR algorithm.[1]

.001 Binary Padding

Rifdoor has added four additional bytes of data upon launching, then saved the changed version as C:\ProgramData\Initech\Initech.exe.[1]

Enterprise T1566 .001 Phishing: Spearphishing Attachment

Rifdoor has been distributed in e-mails with malicious Excel or Word documents.[1]

Enterprise T1082 System Information Discovery

Rifdoor has the ability to identify the Windows version on the compromised host.[1]

Enterprise T1016 System Network Configuration Discovery

Rifdoor has the ability to identify the IP address of the compromised host.[1]

Enterprise T1033 System Owner/User Discovery

Rifdoor has the ability to identify the username on the compromised host.[1]

Enterprise T1204 .002 User Execution: Malicious File

Rifdoor has been executed from malicious Excel or Word documents containing macros.[1]

Groups That Use This Software

ID Name References
G0138 Andariel