Mac OS X 10.5.7 Update
The 10.5.7 Update is recommended for all users running Mac OS X Leopard version 10.5.6, and includes general operating system fixes that enhance the stability, compatibility and security of your Mac.
For detailed information on this update, please visit this website: http://support.apple.com/kb/HT3397
SHA 1 digest = 0173995ad572f2bc11d802671136e5e5c1afe116
For explanation of what a SHA1 digest is, please visit this website: Mac OS X: How to verify a SHA-1 digest.
For detailed information on Security Updates, please visit this website: Apple security updates.