PMD is an extensible multilanguage static code analyzer. The passphrase for the PMD and PMD Designer release signing keys are included in jar published to Maven Central. The private key itself is not known to have been compromised itself, but given its passphrase is, it must also be considered potentially compromised. As a mitigation, both compromised keys have been revoked so that no future use of the keys are possible. Note, that the published artifacts in Maven Central under the group id net.sourceforge.pmd are not compromised and the signatures are valid.
PMD Designer's release key passphrase (GPG) available on Maven Central in cleartext