Pierluigi Paganini January 26, 2014

Attackers breached the email accounts of Microsoft staff, probably with a spear phishing attack, accessing to documents on law enforcement inquiries.

Spear phishing attacks are within most insidious attacks for private companies and organizations, they are primarily caused for data breach occurred in the last couple of years.

Despite the awareness of this type of cyber threat, the number of victims is in constant growth, the last incident involved a “select number” of employees at Microsoft. Microsoft on Friday announced that attackers breached the email accounts of its staff members, accessing to documents on law enforcement inquiries.

“Recently, a select number of Microsoft employees’ social media and email accounts were subjected to targeted phishing attacks. This type of attack is not uncommon, and many companies grapple with phishing attempts from cybercriminals (visit www.microsoft.com/sir). ” Adrienne Hall, General Manager at Microsoft’s Trustworthy Computing Group wrote in a blog post. 

Let’s remember that last Microsoft Law Enforcement Requests Report related to the first half of 2013 reported that the company received a total of 37,196 requests from law enforcement agencies covering 66,539 separate users. The US is well ahead of the field, with 7,014 requests covering  18,809 users.

The attackers have conducted their offensive against both email and social media accounts of Microsoft’s employees, the company did not reveal how many documents might have been exposed neither the nature of the attackers.

“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,” 

“It appears that documents associated with law enforcement inquiries were stolen. If we find that customer information related to those requests has been compromised, we will take appropriate action,” added Hall.

Spear phishing is a variant of phishing attack against a restricted group of selected targets, usually it is an email-spoofing fraud attempt that hits a specific organization or company, seeking unauthorized access to sensitive data. Unlike a phishing attack, the spear phishing attack doesn’t address a wide audience, but it is conducted by attackers that are more interested in intellectual property, trade secrets, or military information instead of financial gain.

Typically spear phishing attacks are conducted by state-sponsored hackers and by hacktivists interested to sensitive data, in some cases also cybercriminals could be also interested in gaining access to confidential information to resell it to governments and private companies.

The company is still investigating on the data breach, recently Microsoft suffered a cyber attacks by the Syrian Electronic Army that for a second time in 2014 a few weeks hacked MSFTNews Twitter account to send out SEA messages.

“In terms of the cyberattack, we continue to further strengthen our security,” “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.” said Hall.

Microsoft security experts don’t exclude that behind the attack there is Syrian Electronic Army may be behind the attacks. 

Pierluigi Paganini

(Security Affairs –  Microsoft, Spear phishing)