In the question it states that the anti-virus is already preventing the file from executing, but it did not remove the file from the device. Later, more developers tried to DOWNLOAD and execute the same file. If the anti-virus is already preventing the execution of the file, then the real issue is the downloading of the file. By blocking the download, you can prevent anyone else from downloading that file while the AV is already preventing the execution of it. Unless by "blacklist" they also mean automatic deletion of said file when discovered and/or prevent it from being downloaded too.