S0660Clambling

[Clambling](https://attack.mitre.org/software/S0660) is a modular backdoor written in C++ that has been used by [Threat Group-3390](https://attack.mitre.org/groups/G0027) since at least 2017.(Citation: Trend Micro DRBControl February 2020) Documented platforms: Windows. Attributed to ATT&CK group: Threat Group-3390. Catalogued in ATT&CK 14.1. 2 references curated.