Old Microsoft Office Exploits Still Wreaking Havoc

Attackers are evolving their techniques to get a better return, but the biggest risks remain old, unpatched flaws, according to new research from SophosLabs.

Office flaws

New research published May 3 by SophosLabs reveals that even while attackers continue to design custom-tailored lures to exploit users, the inconvenient truth is that the most popular vulnerabilities are issues that have been patched years ago.

Instead of just sending random emails, SophosLabs has found an increasing use of what it refers to as "Designer" cyber-threats.

"The details are correct [language, grammar, etc.], leading to far higher victim yields," Chester Wisniewski, senior security adviser at Sophos, told eWEEK. "Some have gone as far as to combine information from data breaches like victims' home addresses."

Going a step further, SophosLabs is seeing increased use of targeted attacks that are specifically localized for the victims. That is, attackers are using specific types of malware depending on where victims are located. The idea of a targeted attack—spear phishing emails, in particular—is not a new one, though it has apparently undergone an evolution in recent months.

"In the past, most localization focused primarily on banking malware, and even then much of it was spread far more widely than was effective at finding the right victims," Wisniewski said.

For example, he noted that Bank of America spam targeting Australians wasn't uncommon, even though it wasn't an attack lure that should appeal to Australians.

"Now exploit kit retailers want the maximum dollar return per victim regardless of location," Wisniewski said. "It isn't entirely new, just refined and getting more common and successful as they figure out better ways to target us."

SophosLabs also specifically looked at attack exploits related to Microsoft Office documents during the fourth quarter of 2015. According to the analysis, the CVE-2012-0158 Office exploit was used in approximately 48 percent of reported incidents. Although CVE-2012-0158 was patched by Microsoft more than three years ago, for various reasons it remains very popular and is exploited regularly.

"One reason is that we're terrible at patching," Wisniewski said.

Failure to patch is a trend that other vendors have observed this year, including the recent Verizon 2016 Data Breach Investigations Report (DBIR). According to the DBIR, 85 percent of all successful exploits in the last year can be attributed to 10 already patched vulnerabilities. In some cases, the patches have been available for years.

CVE-2012-0158, in particular, remains popular, simply because it continues to work, according to Wisniewski. He noted that creating a reliable exploit that is compatible with a wide variety of PCs is difficult, and CVE-2012-0158 is a solidly reliable exploit against unpatched Office. Simply opening the malicious document leads to remote code execution.

"It is slowly losing ground to newer exploits, but has been used by many groups without the skill to use newer and more complicated exploits," Wisniewski said.

Sean Michael Kerner is a senior editor at eWEEK and InternetNews.com. Follow him on Twitter @TechJournalist.

Sean Michael Kerner

Sean Michael Kerner

Sean Michael Kerner is an Internet consultant, strategist, and contributor to several leading IT business web sites.