The ACC controller was running under the apm user, the monitored application was running under a different user in the same user group
The particular package was created with following permissions:
$ ll /opt/ca/wily/extensions/deploy/servlets-2c9085b-10.5.2.15.tar.gz
-rw------- 1 apm apm /opt/ca/wily/extensions/deploy/servlets-2c9085b-10.5.2.15.tar.gz
It was discovered the umask for the apm user was 077 which creates files with restricted permissions that only the owner of the file, apm, can read and write.