[WellMail](https://attack.mitre.org/software/S0515) is a lightweight malware written in Golang used by [APT29](https://attack.mitre.org/groups/G0016), similar in design and structure to [WellMess](https://attack.mitre.org/software/S0514).(Citation: CISA WellMail July 2020)(Citation: NCSC APT29 July 2020)
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.