Connect with us

Hi, what are you looking for?

SecurityWeekSecurityWeek

Incident Response

Users File Lawsuit Against Yahoo Over Data Breach

Several class actions have been filed against Yahoo in California and Illinois over the recently disclosed data breach that affected at least 500 million accounts.

Several class actions have been filed against Yahoo in California and Illinois over the recently disclosed data breach that affected at least 500 million accounts.

Plaintiffs are mainly displeased with the fact that Yahoo has failed to protect their personal information, but they also pointed to how long it took the company to detect and disclose the attack. Some of them believe their details had already been misused by cybercriminals before Yahoo confirmed the breach.

In one of the California lawsuits, the plaintiffs referenced a Ponemon Institute study which estimates that the average time to detect an attack is 191 days. They highlighted in the complaint that it took Yahoo nearly two years, which they believe is an “unusually long period of time.”

Yahoo revealed last week that hackers likely sponsored by a nation state breached its systems in late 2014. The company said the attackers accessed names, email addresses, phone numbers, dates of birth, bcrypt-hashed passwords and, in some cases, encrypted or unencrypted security questions and answers.

According to some reports, Yahoo discovered this breach while conducting an investigation into claims that someone had stolen 200 million user accounts in 2012. Yahoo reportedly launched the investigation in July, but it failed to inform Verizon, which has agreed to buy the company’s core business for $4.8 billion.

Yahoo stock surged after the Verizon acquisition announcement, but it dropped from $44.83 to $42.42 following news of the massive breach.

The company has not shared any information on which country might be behind the attack. Experts have speculated that it could be any one of the United States’ biggest cyberspace “enemies,” including Russia, China or North Korea.

Yahoo’s weak security controls

Advertisement. Scroll to continue reading.

The users who filed lawsuits against Yahoo allege that the company misrepresented the safety of its systems and services, and the findings of security experts seem to back these claims, particularly when it comes to cryptographic controls.

Venafi, a company that specializes in securing cryptographic keys and digital certificates, conducted an analysis of external Yahoo websites and discovered several problems. Researchers determined that more than a quarter of the certificates on the company’s sites have not been reissued since January 2015. Venafi pointed out that replacing certificates after a massive breach is critical to prevent attackers from accessing encrypted communications.

Another problem is that many of the certificates use MD5 and SHA-1 cryptographic hashing functions, which are no longer considered secure.

Related: UK Man Involved in 2012 Yahoo Hack Sentenced to Prison

Related: Yahoo Pressed to Explain Huge ‘State Sponsored’ Hack

Related: Russia? China? Who Hacked Yahoo, and Why?

Written By

Eduard Kovacs (@EduardKovacs) is a managing editor at SecurityWeek. He worked as a high school IT teacher for two years before starting a career in journalism as Softpedia’s security news reporter. Eduard holds a bachelor’s degree in industrial informatics and a master’s degree in computer techniques applied in electrical engineering.

Click to comment

Trending

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

Join the session as we discuss the challenges and best practices for cybersecurity leaders managing cloud identities.

Register

SecurityWeek’s Ransomware Resilience and Recovery Summit helps businesses to plan, prepare, and recover from a ransomware incident.

Register

Expert Insights

Related Content

Cybercrime

A recently disclosed vBulletin vulnerability, which had a zero-day status for roughly two days last week, was exploited in a hacker attack targeting the...

Data Breaches

LastPass DevOp engineer's home computer hacked and implanted with keylogging malware as part of a sustained cyberattack that exfiltrated corporate data from the cloud...

Incident Response

Microsoft has rolled out a preview version of Security Copilot, a ChatGPT-powered tool to help organizations automate cybersecurity tasks.

Data Breaches

GoTo said an unidentified threat actor stole encrypted backups and an encryption key for a portion of that data during a 2022 breach.

Application Security

GitHub this week announced the revocation of three certificates used for the GitHub Desktop and Atom applications.

Incident Response

Meta has developed a ten-phase cyber kill chain model that it believes will be more inclusive and more effective than the existing range of...

Cloud Security

VMware described the bug as an out-of-bounds write issue in its implementation of the DCE/RPC protocol. CVSS severity score of 9.8/10.