Credit card hacked? Four steps to take.

Credit card hackers can send sophisticated looking e-mails and make small purchases on credit cards to test if you're watching closely. 

The latest security breach involving credit-card data serves as an important reminder for cardholders to take precautions in order to protect their personal information.

As many as 1.5 million MasterCard and Visa cards in North America may have been affected in the breach involving Global Payments.

Even if they haven't noticed anything amiss yet, the danger has hardly passed. Being part of a breach makes an individual six times more likely to be the victim of fraud or identity theft, according to Javelin Strategy & Research.

Here's what to do if you suspect your data has been breached:

BE EXTRA CAUTIOUS.

Being extra careful and watching for signs of possible trouble is important. When hackers glean consumer information through attacks like the breach at Global Payments, they can use it to mine more data online about those individuals. That makes it easier to send targeted emails that mimic messages from a consumer's bank — a process known as "spear phishing," a more sophisticated version of the phony email efforts known as "phishing" in that they incorporate your personal information.

REVIEW STATEMENTS CLOSELY.

Keep a close eye out for unexpected charges on your financial statements. Even a $1 charge could be a sign that a thief has your account number and is testing to see if you notice anything unexpected. If you spot any unauthorized purchases, a call to the credit card company will start an investigation and the questionable purchases will be reversed under most circumstances. Companies also will issue new account numbers upon request.

If you don't receive your statement on time, that may be a red flag that something isn't right. One popular tactic with thieves is changing the billing address on existing accounts to delay their detection.

UPDATE SOFTWARE AND BROWSERS.

Protect yourself from online fraud and identity theft with browser security software on your computers and mobile devices. If you already have anti-virus software, make sure to update it.

Be sure to use the most recent version of your Internet browser. Older versions can have security weaknesses that leave you at risk. Also, set your anti-virus and anti-spyware software to auto-update and use an Internet firewall.

MONITOR YOUR CREDIT REPORT.

The three national credit reporting companies — Equifax, Experian and TransUnion — are required by law to provide consumers with one free credit report each year, upon request. The reports can be obtained at www.annualcreditreport.com or by mail.

If you believe there may be a problem, considering asking them to put a fraud alert and possibly a security freeze on your credit information.