Heralds of Genesis

A shadowy group of saboteurs and assassins that Network Intelligence has clashed with multiple times. On 156,072-29, the day of Rimtreader's destruction, Vesqua intercepted communications from somewhere onboard using a decryption key she recognized as belonging to this group.

Vesqua also told you they weren't a galaxy-spanning group like Nullspace, but that they usually appear deep within Network space; it would be unusual for them to be active this far out.