The bear economy is creating a bull market for cyber-crooks.
Experts and law-enforcement officials who track Internet crime say scams have intensified in the past six months, as fraudsters take advantage of economic confusion and anxiety to target both consumers and businesses.
Thieves are sending out phony e-mails and putting up fake Web sites pretending to be banks, mortgage-service providers or even government agencies such as the Federal Bureau of Investigation or the Federal Deposit Insurance Corp.
Cellphones and Internet-based phone services have also been used to seek out victims. The object: to drain customer accounts of money or to gain information for identity theft.
Avivah Litan, vice president with Internet-technology research company Gartner Inc., said clients are telling her that cyber-assaults on many banks have doubled in the past six months in the U.S. and other parts of the world, including the U.K., Canada, Mexico and Brazil.
Though most are thwarted by computer-security defenses, such as spam filters and fraud-detection systems, that still leaves potentially millions of victims.
"They are all experiencing a lot more attacks, and a lot more ATM fraud" aimed at depositors' accounts, Ms. Litan said.