[MuddyViper](https://attack.mitre.org/software/S9032) is custom backdoor written in C and C++ used by [MuddyWater](https://attack.mitre.org/groups/G0069) for command and control (C2) communications and persistence. [MuddyViper](https://attack.mitre.org/software/S9032) is loaded by [Fooder](https://attack.mitre.org/software/S9033) and sends frequent messages to the C2 server.(Citation: ESET_MuddyWater_Dec2025)
Platforms: Windows
MITRE ATT&CK® is a registered trademark of The MITRE Corporation. © 2026 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation.