PNC Financial Services Group appeared to be the latest target in a wave of cyber attacks that have disrupted the online banking operations at major U.S. banks in recent days.
A group claiming responsibility for the attacks threatened to hit Pittsburgh-based PNC Thursday, but some customers began experiencing problems on Wednesday.
"PNC is aware of the threat and is taking appropriate action," spokesman Fred Solomon said Wednesday afternoon. He said some customers in the Midwest were having trouble accessing the bank's website on the first attempt, "but generally our systems are operating normally."
A series of so-called denial of service attacks, which flood websites with communications requests, started last week with Bank of America and JPMorgan Chase. Wells Fargo was victimized Tuesday while U.S. Bancorp was hit Wednesday.
This type of attack, also called a flooding attack, is one of the oldest forms of Internet attacks and is fairly common, said David Brumley, assistant professor and cyber security expert at Carnegie Mellon University's CyLab.
"That's a lot different than actually hacking into a bank," he said. "Customers may have problems accessing the website, but the bank data is still secure and safe."
His best advice for PNC customers was to be patient.
"In the worst case, you'll have to go to the bank" or an ATM to access an account, he said.
Jason Maloni, senior vice president at crisis communications firm Levick in Washington, D.C., said that unless an outage were to last for an extended period, it shouldn't hurt PNC's reputation or cause the bank to lose customers.
"This attack is industrywide. It's not something PNC was singled out for," he said. "It's the new normal. Credit card companies have been subject to this for some time."
A group calling itself the Izz ad-Din al-Qassam Cyber Fighters has claimed responsibility for the bank outages. It said the attacks would continue until a video insulting the Islamic prophet Muhammad was removed from the Internet.
But Mr. Maloni said it remained to be seen who was behind the cyber attacks.
"I wouldn't read too much into that. It seems very neat and tidy," he said.
Sen. Joe Lieberman, chairman of the U.S. Senate's Homeland Security committee, last week blamed the attacks on Iran, saying they were in response to increasingly strong economic sanctions backed by the U.S. and its allies.
Patricia Sabatini: firstname.lastname@example.org or 412-263-3066.