This problem started up after installation of gnu bind. It's more up to date than the one shipped with Solaris 10.
This error message: /usr/lib/security/pkcs11_softtoken.so unexpected failure in ELF signature verification. System may have been tampered with. See cryptoadm(1M). is generated whenever any verification requiring crypto occurs. This includes ssh-ing into the box. ftp (which does not use crypto) is fine. elfsign list -f issuer -e pkcs11_softtoken.so.1 returns Unable to open pkcs11_softtoken.so.1 as an ELF object -- This message posted from opensolaris.org