Disruptions to businesses in South Korea continue today after hackers used wiper malware to take a number of banks and television networks offline yesterday. A number of financial systems at a half-dozen banks and production systems inside South Korea’s major television networks remain down, kicking off speculation as to who is behind the attacks and how they got in.

In an alert issued by the Office of the Comptroller of the Currency (OCC), Deputy Comptroller for Operational Risk Carolyn G. DuChene warned financial and other critical institutions about the wave of ongoing distributed denial of service (DDoS) attacks targeting their networks. DuChene is urging the banks in particular to share data about the attacks with one another and reiterated the OCC’s expectation that banks have risk management plans designed to mitigate such attacks in place ahead of time.

PNC Bank appears, as promised, to be the latest victim of hacktivists carrying out denial-of-service attacks against major U.S. financial services institutions. PNC, out of Pittsburgh, joins Wells Fargo, J.P. Morgan Chase & Co. and Bank of America on a list of banks taken offline reportedly by a group who claimed responsibilities for the attacks as retaliation for the portrayal of Muslims in “Innocence of Muslims,” a series of movie trailers uploaded to YouTube.

Subscribe to our newsletter, Threatpost Today!

Get the latest breaking news delivered daily to your inbox.