Netskope Threat Labs publishes a monthly summary blog post of the top threats we are tracking on the Netskope platform. The purpose of this post is to provide strategic, actionable intelligence on active threats against enterprise users worldwide.
Summary
- After some time out of the first place, PDF file types returned as the most common file type for malware downloads, followed by ZIP archives and EXE (PE) binary files. These three file types were the top three in the list for several months and show a very strong preference for the attackers.
- Attackers continue to attempt to fly under the radar by using cloud apps to deliver malware, with 50% of all malware downloads in November originating from 189 cloud apps, the highest number of the year.
- Well-known malware such as the AgentTesla infostealer and Loda RAT were among the top malware families detected on the Netskope platform in November, as well as the Phobos Ransomware.
Cloud Malware Delivery
Attackers attempt to fly under the radar by delivering malicious content via popular cloud apps. Abusing cloud apps for malware delivery enables attackers to evade security controls that rely primarily on domain block lists and URL filtering, or that don’t inspect cloud traffic. In November 2023, 50% of all HTTP/HTTPS malware downloads originated from popular cloud apps, the lowest value of the past six months.
The total number of cloud apps from which malware downloads originated is the highest of the whole year, with 189 distinct cloud apps used for malware downloads.
Attackers achieve the most success reaching enterprise users when they abuse cloud apps that are already popular in the enterprise. Microsoft OneDrive, the most popular enterprise cloud app, has a