The new year is a time for resolutions and promises of change, so much so that even malware has returned from a bit of time off with some new features, including a new Flash exploit, according to Malwarebytes head of investigations, Jérôme Segura.
The Fallout exploit kit (EK) took a little respite over the first few weeks of 2019, but it has returned, this time using CVE-2018-15982, along with HTTPS support, a new landing page format, and Powershell to run its payloads. In addition, Seguara said the team has seen an increase in RIG EK campaigns, which he suspects might have been an effort to fill that temporary void.
As the malware has returned to business, it continues to spread using malvertising chains. In September 2018, FireEye wrote that the Fallout EK was discovered affecting mostly countries in the Asia Pacific region. Though it did distribute SmokeLoader in Japan, the malware then shifted to dropping GandCrab in the Middle East.
When the malware was detected again in October 2018, the EK was being used in the HookAds campaign, which delivered victims to a fraudulent dating page, according to Malware-Traffic-Analysis.net, which also noted that the first payload was the Minotaur ransomware, followed by AZORult during the second and third runs.
Since Fallout EK’s return, Malwarebytes researchers have discovered the malware is delivering the GandCrab ransomware, though it delivers its payload via Powershell, as opposed to iexplore.exe. “This technique is most likely an attempt at evasion, as traditionally we’d expect the Internet Explorer process to drop the payload,” Segura wrote.
“What this new development tells us is that exploit kit developers are still monitoring the scene for new exploits and techniques,” he continued. “In 2018, several zero-days for Internet Explorer and Flash Player were found and turned into easily adaptable proofs of concept. Even though the market share for IE and Flash continues to drop, there are many countries still running older systems where the default browser is Internet Explorer.”