The UNIX program COPS scans a

The COPS program itself could be modifed by an intruder to disable some of its features or even to take advantage of its features to create new security flaws.Even if COPS is not cracked,it is possible for an intruder to gain acopy of COPS,study it,and locate security breaches which COPS does not detect,Then that intruder could prey on systems in which the management depends on COPS for security (thinking it is providing security ),when all COPS is providing is management complacency.
COPS could be stored on a read only media or file system to avoid its modification.It could only be provided to bona fide systems managers to prevent it from falling into the wrong hands.Neither of these is a foolproof solution,however.