A "leakster" is someone who secretly reveals or exposes confidential or private information to the public, often found in journalism or whistleblowing.
Several ads for a «Huawei PCE Series» phone were leaked by popular leakster Evan Blass on Twitter. (indianexpress.com)
The leak comes from serial leakster @evleaks. (maktechblog.com)
In addition, a few days ago we got a glimpse of the XL's smaller brother, courtesy of serial leakster Evan Blass (better known as @evleaks). (neowin.net)