Hackers managed to steal a database containing customer credentials and contact information from PR Newswire, a major press release distribution service that's used by tens of thousands of companies and public relations agencies.
The database was discovered on the same hacker server where stolen source code for several Adobe products was recently found, suggesting that the same attackers might be responsible for both incidents, according to Alex Holden, chief information security officer of Hold Security, a company that monitors the Internet underground for stolen business data.
The same group of cybercriminals are believed to have also hacked into computer systems belonging to several major data brokers including Dun and Bradstreet, LexisNexis and Kroll Background America.
"Cleverly disguised as an image, an archive of PR Newswire was found on hackers' repository server," Hold Security said Wednesday in a blog post. "The database date appears to be from March 8, 2013 but it is unclear yet if the breach had happened at the same time or at a later date as the archive was created on April 22, 2013."
The company worked with independent security reporter Brian Krebs, who alerted PR Newswire of the breach.
PR Newswire, a company owned by marketing and communications services firm UBM, confirmed the breach Wednesday.
"We recently learned that a database, which primarily houses access credentials and business contact information for some of our customers in Europe, the Middle East, Africa and India, was compromised," Ninan Chacko, PR Newswire's CEO, said in a blog post.
"We are conducting an extensive investigation and have notified appropriate law enforcement authorities," Chacko said. "Based on our preliminary review, we believe that customer payment data were not compromised."
PR Newswire told Krebs there were approximately 10,000 records in the compromised database, but that the actual number of affected customers is likely much lower, because customers generally maintain multiple accounts.
PR Newswire has notified affected customers and has enforced a mandatory password reset for their accounts, a PR Newswire spokesman said Thursday. The passwords were hashed, he said.
Hashing is a one-way form of encryption where plaintext data is passed through an algorithm to generate a unique cryptographic representation of it, random-looking string of characters referred to as a hash.
A hash is not meant to be decrypted to recover the original plaintext information, but can be used to validate information inputted at a later time by rehashing it and comparing the results. Modern websites store hashes in their databases instead of passwords for security reasons.
However, once stolen, some password hashes can be "cracked" using brute-force methods, their resistance against such attacks depending on the complexity of the original passwords, the hashing algorithm used and whether other strengthening methods like salting were also applied.
Because of this, if a password hash for an account gets stolen, it's generally a good practice for account owners to change their password on all websites where they might have used it.
"As a general practice, we recommend that our customers use strong passwords and regularly update them, not just on PR Newswire but on any website requiring login credentials," Chacko said.
Hold Security doesn't have any evidence that the stolen data has been abused. However, its theft raises a number of questions about the hackers' motives, the company said.
"Given the financial motivation of this hackers' group, PR Newswire is an unlikely target and it might have been a target of opportunity," Hold Security said in its blog post. "On the other hand, considering the criticality of major announcements done through PR Newswire, it is possible that savvy malicious individuals might use unannounced press releases or even manipulate major announcements to gain a competitive financial edge on the stock market."
There have been cases of fake announcements being distributed by press release distributors before and ending up influencing stock markets.
On Oct. 11, a Swedish press release distributor called Cision retracted an announcement that Samsung planned to acquire Fingerprint Cards, a Swedish maker of biometric sensors, after the press release turned out to be fake. The fraudulent announcement caused Fingerprint Cards' stock to temporarily surge, adding around $200 million to the company's market value, Businessweek reported.
PR Newswire told Krebs there's no evidence to believe at this time that the data breach it suffered is related to the Cision incident last week.
The company has strong technical and human safeguards in place designed to limit the risk of fraudulent press releases being distributed through its service, a PR Newswire spokesman said Thursday.