Trend Micro Incorporated has lately been seeing a lot more of the "fileless" kind of malware attacks. In its mid-2019 roundup report, Trend Micro says that there has been a surge in fileless attacks that were designed to use this approach to disguise malicious activity. Detections of this kind of threat alone by them were up 265% compared to the first half of 2018.
They also found that exploit kits have also made a resurgence, with a 136% increase in EK detection by them compared to the same time in 2018. But even Trend admits that, "The number for the first half of 2019 was still a far cry from when exploit kits were at their peak."
But the "living off the land" style attack was also a big player in the threat scene over the last six months. These kinds of attack do not write to disk, are usually executed in a system's memory, reside in the registry, or misuse normally whitelisted tools like PowerShell, PsExec or Windows Management Instrumentation. They use the resources they find available to them from a standard Windows installation so that they don't have to bring special files or tools along with them.
But there can be a blurring of the category lines here. One notable exploit kit from the first half of 2019 was Greenflash Sundown, which was used by the ShadowGate campaign through an upgraded version which was capable of living off the land. It did this trick by using an updated PowerShell loader to filelessly execute the payload, which was a cryptominer targeted at South Asia.
Ransomware was a category of attack much used in the beginning of the year. The organizations that they saw as the most affected were operating in the manufacturing, government, education and healthcare industries. Organizations in finance, technology, energy, food and beverage, as well as oil and gas industries, did not escape ransomware either.
Also, there seemed to be a change in the way the ransomers operated. They may have considered that they could consistently earn as much (or even more) by zeroing in on multinationals, large enterprises and even government organizations. The places with money, right? They seem to have gone for it.
Their new method entailed reconnoitering their target, sending its employees tailored phishing emails, and searching for security gaps that they could exploit to gain access to and laterally move within its networks and systems.
Trend thinks the malefactors are getting bolder. The report says that, "The emboldened attacks and higher ransom demands could have also been spurred by their malware's having been outfitted with destructive routines beyond file encryption, serving as fail-safes to maximize impact. With foolproof mechanisms that could lessen the chances for victims to recover their systems or files, ransomware operators could be further motivated into intimidating and demanding heftier ransom payments from their victims."
They also think just endpoint security alone may not be enough. "Employing multilayered threat defense solutions -- from the gateways, servers, and networks to endpoints -- can help thwart ransomware at each layer of their online infrastructures," is the way that they put it.
— Larry Loeb has written for many of the last century's major "dead tree" computer magazines, having been, among other things, a consulting editor for BYTE magazine and senior editor for the launch of WebWeek.