Internet crime is becoming a major commercial activity, according to a report by the security firm, Symantec.
Its report into threats to internet security describes underworld auction sites where bank details and credit cards are on sale.
Commercial software used by criminals to launch attacks on websites is also being traded, the report says. It also warns that criminals are using trusted sites like MySpace and Facebook to launch attacks on users' computers.
The BBC's technology correspondent Rory Cellan-Jones said: "Until recently young hackers who spread viruses or launched attacks on computer networks were bent on mischief rather than money making."
However, this latest report suggests such attacks are now part of a multi-billion dollar criminal industry.
It highlights online discussion boards where members buy and sell the kind of information that enables identity theft.
Our correspondent said in recent days sellers on one of these sites were offering everything from 100million email addresses to bank logins and credit card details.
Elsewhere, phishing kits are on sale enabling buyers to set up fake banking sites to lure unsuspecting customers.Internet, Web, Internet Crime, Crime
Source:→ BBC News