A group calling itself “Shadow Brokers” says it’s releasing another tranche of information from its trove of top secret hacking data stolen from the U.S.’s National Security Agency.

Shadow Brokers has been closely followed by intelligence watchers and cybersecurity specialists since the group released a set of NSA hacking tools into the wild in August, purportedly the opening act in an implausible money-raising stunt.

The Intercept, an investigative publication with access to NSA material leaked by former intelligence contractor Edward Snowden, confirmed Shadow Brokers’ tools were real by cross-referencing the leaked data with information held in a previously unpublished top secret manual.

The authenticity of the latest batch of material could not immediately be established. The Shadow Brokers did not return messages seeking comment Monday. The NSA declined to comment.

(AP)