HAMMERTOSS is a backdoor that was used by APT29 in 2015. [1] [2]

ID: S0037
Associated Software: HammerDuke, NetDuke
Platforms: Windows
Version: 1.2
Created: 31 May 2017
Last Modified: 09 February 2021

Techniques Used

Domain ID Name Use
Enterprise T1071 .001 Application Layer Protocol: Web Protocols

The "Uploader" variant of HAMMERTOSS visits a hard-coded server over HTTP/S to download the images HAMMERTOSS uses to receive commands.[1]

Enterprise T1059 .001 Command and Scripting Interpreter: PowerShell

HAMMERTOSS is known to use PowerShell.[1]

Enterprise T1001 .002 Data Obfuscation: Steganography

HAMMERTOSS is controlled via commands that are appended to image files.[1]

Enterprise T1573 .001 Encrypted Channel: Symmetric Cryptography

Before being appended to image files, HAMMERTOSS commands are encrypted with a key composed of both a hard-coded value and a string contained on that day's tweet. To decrypt the commands, an investigator would need access to the intended malware sample, the day's tweet, and the image file containing the command.[1]

Enterprise T1567 .002 Exfiltration Over Web Service: Exfiltration to Cloud Storage

HAMMERTOSS exfiltrates data by uploading it to accounts created by the actors on Web cloud storage providers for the adversaries to retrieve later.[1]

Enterprise T1564 .003 Hide Artifacts: Hidden Window

HAMMERTOSS has used -WindowStyle hidden to conceal PowerShell windows.[1]

Enterprise T1102 .003 Web Service: One-Way Communication

The "tDiscoverer" variant of HAMMERTOSS establishes a C2 channel by downloading resources from Web services like Twitter and GitHub. HAMMERTOSS binaries contain an algorithm that generates a different Twitter handle for the malware to check for instructions every day.[1]

Groups That Use This Software

ID Name References
G0016 APT29