By Rob Thubron on October 5, 2016, 6:15 AM
It seems there’s no end to Yahoo’s problems. Last month, the troubled company admittedthat at least 500 million user accounts had been compromised in a breach that took place in 2014. It claimed “state-sponsored actors” were responsible for the attack, though a security firm disputes this. Now, it’s been revealed that Yahoo secretly built custom software last year that scanned all of its customers’ incoming emails for information provided by US intelligence officials.
The report comes from Reuters’ Joseph Menn, citing three people familiar with the matter.
Yahoo was complying with a classified US government request when it created the scanning tool that searched hundreds of millions of user emails at the behest of the National Security Agency or FBI. The software was searching for a specific string of characters, though it’s unclear exactly what words or phrases it was looking for and what data, if any, Yahoo handed over to the authorities.
When Yahoo’s internal security team discovered the software, they initial thought it was the work of hackers. Company CEO Marissa Mayer’s decision to comply with the demand led to Chief Security Officer Alex Stamos leaving his position to join Facebook in June 2015. Stamos said a programming flaw could have allowed hackers to access the stored emails.
The incident is the first known case of a company agreeing to an agency’s request to scan all arriving emails, rather than probing stored messages or a small number of accounts in real time. "Yahoo is a law-abiding company, and complies with the laws of the United States," the firm said
