Successful PTH (pass the hash) attacks are becoming increasingly common in the corporate world in recent months, a trend I've witnessed first-hand in the IT security trenches. PTH goes hand-in-hand with the types of infamous APT (advanced persistent threat) attacks that have staggered companies such as RSA, Sony, Dupont, and others, so organizations need to be prepared do defend against them. There's just one surefire way to prevent them: Secure all your systems perfectly.