Recent Phishing Attacks Compromised Employee Email, Social Media Accounts at Microsoft

[Update] Microsoft on Friday said that attackers breached the email accounts of a “select number” of employees, and obtained access to documents associated with law enforcement inquiries.

According to the company, a number of Microsoft employees were targeted with attacks aiming to compromise both email and social media accounts, and in some cases, the attacks were successful.

“While our investigation continues, we have learned that there was unauthorized access to certain employee email accounts, and information contained in those accounts could be disclosed,” Adrienne Hall, General Manager at Microsoft's Trustworthy Computing Group, wrote in a blog post.

“It appears that documents associated with law enforcement inquiries were stolen,” Hall said.

“If we find that customer information related to those requests has been compromised, we will take appropriate action,” Hall continued. “Out of regard for the privacy of our employees and customers – as well as the sensitivity of law enforcement inquiries – we will not comment on the validity of any stolen emails or documents.”

The software giant did not say how many documents might have been obtained or exposed as a result of the attacks, or who they believe may have been behind the attacks.

Targeted attacks like this are not uncommon, especially for an organization like Microsoft. What’s interesting about this is that the incident was significant enough to disclose, indicating that a fair number of documents could have been exposed, or that the company fears some documents will make their way to the public if released by the attackers—which may be the case if this was a “hacktivist” attack.

“In terms of the cyberattack, we continue to further strengthen our security,” Hall continued. “This includes ongoing employee education and guidance activities, additional reviews of technologies in place to manage social media properties, and process improvements based on the findings of our internal investigation.”

In a Microsoft Law Enforcement Requests Report covering the first half of 2013, Microsoft (including Skype) said that it received 37,196 requests from law enforcement agencies potentially impacting 66,539 accounts.

Microsoft has recently faced a barrage of attacks claimed by the Syrian Electronic Army (SEA), hackers who support President Bashar al-Assad's regime. While no attacks have yet resulted in any significant data loss or company-wide impact, the company did have social media accounts and blogs compromised earlier this month.

According to Microsoft, the Syrian Electronic Army may be behind the attacks.

“Our current information suggests the phishing attacks are related,” Hall told SecurityWeek in an emailed statement.

Updated 10/24/14 10:32PM: Added statement from Microsoft on the attacks possibly being related.

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