Distribution or use of OpenBullet 1.2.2 against systems you do not own or do not have explicit permission to test is a in most jurisdictions. The author of OpenBullet explicitly states:
If your interest is academic research into malicious tooling: openbullet 1.2.2
This article explores the technical aspects, features, and the context surrounding version 1.2.2. Distribution or use of OpenBullet 1