In light of a massive security breach that revealed the information of 70 million Target customers, the FBI has begun warning retailers to expect similar intrusions. Reuter reports that the bureau has discovered 20 cases that used software similar to what was used against Target.

The brief, confidential report given to retailers dated January 17 described "malware that infects point-of-sale (POS) systems, which include cash registers and credit-card swiping machines found in store checkout aisles." The malware takes advantage of the brief window in a computer's RAM when credit card information is unencrypted.

While Target as well as Nieman Marcus have reported hacks in recent months, sources also said that the systems of other retailers were broken into as well.

One reputable cybercrime firm has reported that at least six other stores were attacked in a fashion similar to Target, though that number was not confirmed by a second party. The specific RAM scraper, BlackPOS was supposedly developed by a Russian teenager and then sold to others.

As is always the case when data breaches like this happen, remember the basic security measures you can take: use different passwords, review your credit card statements, never give out your personal information to sketchy sources, and do not ever use computers or log on to the internet.