IT Trends

Internet Security Report: Fileless Malware on the Rise, Defenses Failing

• By David Nagel
• 06/24/21

Seventy-five percent of malware is going undetected by “traditional malware solutions,” according to a new report. And 74% of threats detected in the last quarter were zero-day malware, an all-time high, according to the researchers.

The report, the Internet Security Report for Q1 2021 from WatchGuard Technologies, found that malicious scripts are delivering fileless malware in the form of an XML external entity. The most widespread was XML.JSLoader, which made the top 10 for the first time in the first quarter of 2021. According to researchers: “The sample WatchGuard identified uses an XML external entity (XXE) attack to open a shell to run commands to bypass the local PowerShell execution policy and runs in a non-interactive way, hidden from the actual user or victim. This is another example of the rising prevalence of fileless malware and the need for advanced endpoint detection and response capabilities.”

A ransomware loader called Zmutzy made the top 2 in Q1. It manifests as a disguised email attachment. According to the researchers: “Associated with Nibiru ransomware specifically, victims encounter this threat as a zipped file attachment to an email or a download from a malicious website. Running the zip file downloads an executable, which to the victim appears to be a legitimate PDF. Attackers used a comma instead of a period in the file name and a manually adjusted icon to pass the malicious zip file off as a PDF. This type of attack highlights the importance of phishing education and training, as well as implementing back-up solutions in the event that a variant like this unleashes a ransomware infection.”

The report highlighted a number of other trends in malware and network attacks as well.

• Half of the top-10 malware families by volume were new to the top-10, including Ursu, Trojan.IFrame, XML.JSLoader, Zmutzy, and Zum.Androm;

• Encrypted connections saw less zero-day malware (60.3%) than the overall average (74%);

• Network attacks reached a three-year high during the first quarter, at 4.2 million Intrusion Prevention Service (IPS) hits on Firebox appliances;

• More than 5 million malicious domains were blocked by DNSWatch in the quarter, a 281% increase over Q4 2020.

• Exploits against ProxyLogin Exchange Server flaws increased 1,600%.

A complete report and executive summary can be downloaded here. An infographic with highlights from the report can be accessed here.