In the same week that TJX Companies reported what could be one of the largest data losses in recent memory, three major financial institutions report that they also may have exposed the personal information of large numbers of customers.

The data losses have dealt a nasty collective blow to the banking and credit industry, which yesterday was digging out from a raft of credit card re-issues necessitated by TJX's revelation that its systems had been hacked and customer accounts pilfered. At least ten banks in Massachusetts reported customer thefts resulting from the intrusion, and experts say they still don't know how bad the breach is.

Meanwhile, in Sweden, the tailor-made Trojan that led to thefts from scores of Nordea customer accounts was dressed up as a "spam fighting" application, and it was probably sent by Russian-organized criminals, authorities say.

Most of Nordea's customers were not running antivirus applications, according to reports. The bank is absorbing the force of the attack on its own -- all of the affected customers have received a refund of their stolen funds. Some of the larger fraudulent transactions were observed and flagged, according to bank officials, but the criminals managed to complete many smaller transactions.

The news was more uncertain in Canada, where CIBC learned of its missing hard drive around the Christmas holiday. The bank held off notifying customers of the loss at first, hoping that the data could be recovered. Finally, however, officials decided to send a letter to clients to let them know about the incident, and to track any subsequent fraudulent activity.

The drive contains "information relating to the process used to open and administer the accounts," according to CIBC officials. The bank is not providing any further information until the investigation is complete.

The situation is similar at Moneygram, where officials report that servers containing bill payment information were violated, though they have no way to tell whether any of the data was compromised or stolen. Customers have been given a free subscription to a credit monitoring service, officials say, and they are working with law enforcement to determine whether the exposed data is being used by third parties.

Moneygram did not say how its servers were violated, but it represented the breach as a one-time event. "We have taken additional security measures to help ensure this type of incident does not occur again," said Vicki Keller, vice president of Moneygram Global Payment Services.

The impact of data losses like these is substantial, experts say. In a study published earlier this month, the Ponemon Institute estimated that each lost customer record costs a company about $182. Other experts say that businesses lose as many as 30 percent of their online customers following a breach.

— Tim Wilson, Site Editor, Dark Reading