April 13, 2024

Distant Desktop Protocol (RDP) was developed by Microsoft to permit customers, directors, and others to connect with distant computer systems over a community connection utilizing a useful 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. That is why 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 actual fact, that in our common Energetic Adversary Studies our editors are compelled to deal with RDP otherwise 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 Energetic 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 p.c mark – that’s, 9 out of ten IR circumstances embrace RDP abuse. 

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

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

At present, to supply context and recommendation for directors and responders seeking to take care of RDP, we’re publishing a whole package deal of assets – movies, companion articles with extra info, and a constellation of extra scripts and data on our GitHub repository. We’re doing this each to share our Energetic Adversary group’s analysis past the same old long-form reviews we subject, and to supply what we hope is a helpful set of assets for dealing with one in every of infosec’s extra annoying persistent illnesses.  

From an attacker’s viewpoint, concentrating on RDP is a pure selection. Most importantly, it’s a Microsoft-provided software (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 protecting a watch out for it, and an attacker needn’t herald extra instruments which may be detected by EDR or different anti-intrusion instruments. RDP additionally has a comparatively nice graphical person interface that lowers the ability barrier for attackers to browse recordsdata for exfiltration, and to put in and use numerous functions.  

Attackers additionally know that RDP is often misconfigured or misused inside an surroundings, each on servers and sometimes on endpoints themselves. The subsequent article on this RDP assortment appears 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 aspect, there are helpful, sturdy queries that can provide nice perception into exactly how RDP is in use in your community… if you already know the place to look. 

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

 

Distant Desktop Protocol: The Sequence

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