Penetration testing company PacketFocus has experimented with a spear phishing attack -- and found that a wide range of e-mail services and appliances failed to filter it.

"Detailed in a report here, the experiment was conducted in September with the intent of determining the effectiveness of e-mail security controls," writes eWeek's Brian Prince.

"In his test, [PacketFocus CEO Joshua Perrymon] sent a fake LinkedIn e-mail designed to resemble a legitimate LinkedIn invite from Microsoft Chairman Bill Gates... he was able to get the spoofed message around filters 100 percent of the time," Prince writes.

Click here to read the eWeek story.