[Photo credit: i-hacked.com]

PCs get compromised sometimes, and mobile phones, too. But now, in Texas, transportation officials are confirming an exploit against a different type of "device." Instead of proclaiming something like, "Road Closure," a digital sign in Austin was temporarily changed last week to say, "Zombies Ahead."

Authorities remain mystified about how the attack against the sign took place, since it is tamper-proof and outfitted with external locks, according to local newspaper accounts. The sign was switched back to its original message in a matter of hours. Under Texas law, tampering with portable road signs is a misdemeanor punishable by penalties ranging from fines to possible jail time.

However, details of how such an attack can take place were posted last week to the I-hacked.com blog. It's not much of an attack after all, the article notes, mainly because the lock guarding the electronics and the sign control system is small and flimsy. Systems which ask for a password before entering the sign code may often be accompanied by notation, perhaps written in magic marker, revealing the default password.