THE big Singaporel banks - DBS, OCBC and UOB - have once again been targeted by the latest trojan horse computer program, which tricks customers into revealing their Internet banking passwords.

Late last month, banks were alerted to the trojan, which could gain scammers access to customers' accounts.

UOB Bank warned on its website that scammers may be able to 'make unauthorised funds transfers within a short period of time.'

DBS Bank had reportedly more than a million Internet banking customers as of last month. The other two banks declined to reveal how many they had.

The three banks last came under attack by trojans - computer programs infiltrating users' computers - in December, but this latest incarnation can steal Internet banking login information even before the bank's website can encrypt it.

Scammers can sell the account information to other hackers at cyber crime forums to use for mischief, said a spokesman from web security firm Trendlabs.

Not all banking customers will encounter the trojan, but only those whose computers are infected. Trendlabs advises users to 'refrain from visiting malicious Web sites, and opening suspicious links on email, which is usually the source of these types of malware.'

The banks advise customers to update their anti-virus software regularly. If they encounter the trojan, they should call the customer service hotline immediately, and the compromised account will be blocked.

Web security firm F-Secure found 59,177 different banking trojans circulating on the Internet in 2008, up from 15,969 in 2007.

Read the full story in Wednesday's edition of The Straits Times.