San Francisco (AFP) - The US Department of Homeland Security on Friday warned businesses to watch for hackers targeting customer data with malicious computer code like that used against retail giant Target.
A hacker software weapon dubbed Backoff is "compromising a significant number" of businesses large and small, according to an advisory put out by the US Computer Emergency Readiness Team (CERT).
CERT urged those administering point-of-sale systems to check whether Backoff is mining information from transactions and to report any cases to the Secret Service.
"The impact of a compromised PoS system can affect both the businesses and consumer by exposing customer data such as names, mailing addresses, credit/debit card numbers, phone numbers and e-mail addresses to criminal elements," CERT said in an advisory.
"These breaches can impact a business's brand and reputation, while consumers' information can be used to make fraudulent purchases or risk compromise of bank accounts."
Backoff was first identified in 2013 and has been identified as a culprit in a set of Secret Service investigations.
Hackers have evidently been cracking into systems used to remotely access business or store networks and then installing malware to harvest credit card numbers, passwords or other valuable data used for purchases.
Remote access features have become increasingly common as businesses manage systems at diverse locations from central offices or workers link to headquarters from home or the field.
Hackers have been using "brute force" attacks which typically involved computer programs battering accounts with relentless guesses about user names or passwords, according to CERT.
An advisory on the CERT website outlines what business system operators should watch for and suggests ways to deal with Backoff.
US supermarket chain Albertsons, which has 1,060 stores in the United States, and its former owner SuperValu revealed last week that their computer systems were raided by hackers seeking credit card data.
However it was not immediately clear if the data had been stolen.
The hackers attacked sometime between June 22 at the earliest and ended the intrusion July 17 at the latest.
Both said the intrusion was brought under control, and that their customers can make credit and debit card purchases at the stores with no reason to worry.
The break-in is reminiscent of one suffered by retail chain Target, which revealed last year that 40 million bank accounts or credit cards had been compromised when its computer system was hacked from November 27 to December 15.