A staggering 97 percent of the 1,000 largest companies in the Forbes Global 2000 list are at risk of attacks involving the use of stolen credentials belonging to their employees.

Security vendor Digital Shadows recently analyzed stolen credentials dumped online on paste sites, underground forums, and criminal sites from a total of 30,000 disclosed breaches spanning the period between April 2014 and June 2016.

The company cross-checked the stolen credentials against the domains of the 1,000 enterprises and any of their identifiable subsidiaries. In total, Digital Shadows checked 19,362 domains against the stolen credentials and found approximately five million unique email and password combinations from across the 1,000 organizations and their subsidiaries.

The leaked credentials give threat actors a way to target organizations and take over accounts, launch spear-phishing attacks, and to employ credential-stuffing tactics to break into an enterprise network, Digital Shadows said. Other risks involve post-breach extortion attempts and the possibility for threat actors to create botnets with the leaked data.

Companies in the entertainment and technology sectors are far more exposed to credential-based attacks than organizations in almost any other sector. The average number of leaked credentials per company in the entertainment sector was a massive 37,399, while the average for technology companies was 25,806. Healthcare and pharmaceutical companies occupied the number three spot with an average of 3,453 stolen employee email and password combinations available publicly.

Real estate companies, with an average of 395 leaked credentials, fared best among the 12 sectors in the Digital Shadows report.

Digital Shadows found that organizations based in Africa, the US, and United Kingdom are substantially more exposed to leaked credentials than counterparts in, Asia, South America, the Middle East, and to a certain extent, Europe.

LinkedIn Connection

A large proportion of the leaked credentials that Digital Shadows encountered came from breaches at social media companies. For instance, data compromises at LinkedIn, Tumblr, and MySpace alone accounted for almost 60% of the leaked credentials available online for attackers to use. Also contributing to the availability of leaked credentials were gaming and data websites.

Enterprises with employees who reused corporate emails and passwords for such sites can be at risk, Digital Shadows said in its report.

"Organizations really need to practice rules- and roles-based credential management and sanity," to mitigate risks from stolen credentials, says Dr. Shane Shook, an expert on cybercrime, cyber law, and cybercriminal behavior.

When conducting red and blue team engagements with clients, Shook says the most common mistake he has encountered is the failure of companies to restrict or remove entitlements for use of corporate resources.

"Attackers search those out as low-hanging fruit to facilitate their endeavors," he says. Emerging user behavior analytics tools have begun providing some visibility into how credentials are being used, but not always where they exist. Both are important capabilities for organizations to have, Shook adds.

Rick Holland, vice president of strategy at Digital Shadows, says the single most important takeaway from the report is organizations should run multi-factor authentication on all external-facing services such as VPN, Outlook Web Access, and SaaS applications.

They should also implement a policy that states that work-related email accounts shouldn’t be used for personal use.

"Include this policy in security awareness training [and] provide employees with password management solutions for home use," he says. "This approach is similar to providing staff free access to endpoint security solutions for personal use."

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