Google continues to struggle with cybercriminals running malicious ads on its search platform to trick people into downloading booby-trapped copies of popular free software applications. The malicious ads, which appear above organic search results and often precede links to legitimate sources of the same software, can make searching for software on Google a dicey affair.
Google says keeping users safe is a top priority, and that the company has a team of thousands working around the clock to create and enforce their abuse policies. And by most accounts, the threat from bad ads leading to backdoored software has subsided significantly compared to a year ago.
But cybercrooks are constantly figuring out ingenious ways to fly beneath Google’s anti-abuse radar, and new examples of bad ads leading to malware are still too common.
For example, a Google search earlier this week for the free graphic design program FreeCAD produced the following result, which shows that a “Sponsored” ad at the top of the search results is advertising the software available from freecad-us[.]org. Although this website claims to be the official FreeCAD website, that honor belongs to the result directly below — the legitimate freecad.org.
How do we know freecad-us[.]org is malicious? A review at DomainTools.com show this domain is the newest (registered Jan. 19, 2024) of more than 200 domains at the Internet address 93.190.143[.]252 that are confusingly similar to popular software titles, including dashlane-project[.]com, filezillasoft[.]com, keepermanager[.]com, and libreofficeproject[.]com.
Some of the domains at this Netherlands host appear to be little more than software review websites that steal content from established information sources in the IT world, including Gartner, PCWorld, Slashdot and TechRadar.
Other domains at 93.190.143[.]252 do serve actual software downloads, but none of them are likely to be malicious if one visits the sites through direct navigation. If one visits openai-project[.]org and downloads a copy of the popular Windows desktop management application Rainmeter, for example, the file that is downloaded has the same exact file signature as the real Rainmeter installer available from rainmeter.net.
But this is only a ruse, says Tom Hegel, principal threat researcher at the security firm Sentinel One. Hegel has been tracking these malicious domains for more than a year, and he said the seemingly benign software download sites will periodically turn evil, swapping out legitimate copies of popular software titles with backdoored versions that will allow cybercriminals to remotely commander the systems.
“They’re using automation to pull in fake content, and they’re rotating in and out of hosting malware,” Hegel said, noting that the malicious downloads may only be offered to visitors who come from specific geographic locations, like the United States. “In the malicious ad campaigns we’ve seen tied to this group, they would wait until the domains gain legitimacy on the search engines, and then flip the page for a day or so and then flip back.”
In February 2023, Hegel co-authored a report on this same network, which Sentinel One has dubbed MalVirt (a play on “malvertising”). They concluded that the surge in malicious ads spoofing various software products was directly responsible for a surge in malware infections from infostealer trojans like IcedID, Redline Stealer, Formbook and AuroraStealer. Continue reading