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Netskope Threat Labs publishes a monthly summary blog post of the top threats we track on the Netskope platform. This post aims to provide strategic, actionable intelligence on active threats against enterprise users worldwide.
Summary
- OneDrive and SharePoint were on the top of the list of top cloud apps used for malware downloads.
- Attackers continue attempting to fly under the radar by using cloud apps to deliver malware. In March, 59% of all malware downloads originated from a record-setting 235 distinct cloud apps.
- The top malware families active in March included the Infostealer AgentTesla and the Downloader Guloader.
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 don’t inspect cloud traffic. In March 2024, 59% of all HTTP/HTTPS malware downloads originated from popular cloud apps.
The number of apps from which Netskope detected malware downloads increased significantly to a new high of 235 apps.
Attackers achieve the most success in reaching enterprise users when they abuse cloud apps that are already popular in the enterprise. Microsoft OneDrive, the most popular enterprise cloud app, has again held the top spot for the most cloud malware downloads, which it has held for more than six months. Generally, the top three apps have remained largely unchanged compared to the apps used in the last six months. This month observed the return of SharePoint as the second most popular app used for malware download.
The top 10 list reflects attacker tactics, user behavior, and company policy.
Top Malware Families
Attackers constantly create new malware families and variants of existing families to bypass security solutions or update their malware’s capabilities. In March 2024, 68% of all malware downloads detected by Netskope were either new families or new variants that had not been observed in the preceding six months. The other 32% were samples previously observed during the preceding six months and are still circulating in the wild.
The following list contains the top malware and ransomware families blocked by Netskope in March 2024:
- Backdoor.Zusy (a.k.a. TinyBanker) is a banking Trojan based on Zeus’ source code, aiming to steal personal information via code injection into web