Microsoft makes worrying revelations on malware and fraudulent logins

But OS exploits actually declined over the course of 2015

Microsoft has published its biannual security report which contains the usual load of statistics on malware and vulnerabilities.

In terms of the current dangers from malware infections, Redmond's latest Security Intelligence Report – which covers the second half of 2015 – found that in Q4, 20.8% of those PCs running Microsoft security products encountered threats.

And for the first time, as Ars Technica notes, the report contains data from its cloud services, and this includes picking up on fraudulent login attempts for the likes of Office 365.

Microsoft's heuristics are capable of detecting suspicious logins based on iffy looking locations and/or login times, and the company says that over 10 million such dodgy attempts are caught every single day.

In such circumstances, accounts which are thought to have been compromised are forced into validating a second form of authentication – and obviously with the dodgy attempts, the attacker fails to clear the 2FA hurdle.

It's also interesting to learn that Microsoft accounts have in excess of 13 billion logins per day.

Exploits aplenty

As for vulnerabilities, Microsoft observed a rise in vulnerability disclosures of 9.4% in the second half of 2015 compared to the first six months.

And the most common type of exploit encountered was by far the exploit kit, with an encounter rate quadruple that of the next most common – operating system exploits. In fact, operating system exploits actually declined considerably throughout the year, almost halving from Q1 to Q3, although they rose back up slightly in Q4.

The most prevalent exploit kit was Axpergle, and the most targeted operating system flaw was CVE-2010-2568, a vulnerability in Windows Shell.

The report also found that less malware affected managed systems, unsurprisingly, with only a tad over 10% of domain-based PCs encountering malware compared to 22% of non-domain computers in Q4 2015.