April 13, 2024

Distant Desktop Protocol (RDP) was developed by Microsoft to permit customers, directors, and others to hook up with distant computer systems over a community connection utilizing a helpful graphical person interface (GUI). The instruments required for this come as normal on Microsoft Home windows; to provoke and arrange an RDP connection, all of the instruments required to try this are current by default. For this reason RDP is used extensively all through networks by customers and directors to entry distant machines. 

Sadly, it’s additionally generally abused by ransomware teams – so generally, in reality, that in our common Lively Adversary Reviews our editors are pressured to deal with RDP in a different way in graphics so different findings are even seen. And RDP abuse is on the rise, as we see in Determine 1 — numbers from the previous few years of incident-response knowledge as collected by the Lively Adversary Report group. Within the version of the report we’ll be releasing subsequent month, you’ll see that RDP has now cracked the 90 % mark – that’s, 9 out of ten IR instances embrace RDP abuse. 

A bar chart showing the increase in RDP abuse from 2021 to 2023

Determine 1: A primary have a look at the total Lively Adversary dataset from 2023 exhibits that RDP abuse is getting worse 

As we speak, to supply context and recommendation for directors and responders seeking to cope with RDP, we’re publishing a whole bundle of assets – movies, companion articles with further data, and a constellation of further scripts and data on our GitHub repository. We’re doing this each to share our Lively Adversary group’s analysis past the standard long-form stories we situation, and to supply what we hope is a helpful set of assets for dealing with one in all infosec’s extra annoying persistent illnesses.  

From an attacker’s standpoint, concentrating on RDP is a pure selection. Most importantly, it’s a Microsoft-provided instrument (so, a living-off-the-land binary, or LOLBin) that blends in with typical person and administrative conduct. Its utilization alone isn’t apt to attract consideration if nobody’s preserving a watch out for it, and an attacker needn’t usher in further instruments that could be detected by EDR or different anti-intrusion instruments. RDP additionally has a comparatively nice graphical person interface that lowers the talent barrier for attackers to browse information for exfiltration, and to put in and use varied functions.  

Attackers additionally know that RDP is often misconfigured or misused inside an atmosphere, each on servers and sometimes on endpoints themselves. The subsequent article on this RDP assortment seems at simply how widespread such publicity is, and whether or not measures comparable to switching off RDP’s ordinary 3389 port makes a distinction. (Spoiler: No.)  

Rounding out the dismal RDP image, we see self-owns comparable to lack of segregation, use of weak credentials, disabling (by directors) of potential protections comparable to NLA (network-level authentication), and flagrant disregard for greatest practices comparable to least privilege. On the brighter facet, there are helpful, sturdy queries that may give nice perception into exactly how RDP is in use in your community… if you realize the place to look. 

So, to supply context and recommendation for directors and responders seeking to cope with RDP, we’re beginning with a whole bundle of assets – six movies, six companion articles with further data, and a constellation of further scripts and data on our GitHub – with extra to be added over time as occasions dictate.  

 

Distant Desktop Protocol: The Collection

Half 1: Distant Desktop Protocol: Introduction ([you are here], video)
Half 2: Distant Desktop Protocol: Uncovered RDP (is harmful) (submit, video)
Half 3: RDP: Queries for Investigation (submit, video)
Half 4: RDP Time Zone Bias (submit, video)
Half 5: Executing the Exterior RDP Question (submit, video)
Half 6: Executing the 4624_4625 Login Question (submit, video)
GitHub question repository: SophosRapidResponse/OSQuery
Transcript repository: sophoslabs/video-transcripts
YouTube playlist: Remote Desktop Protocol: The Series