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As a redteamer I guarantee you that a Windows endpoint without EDR is caviar for us...


Are there publicly known exploits which allow RCE or data extraction on a default windows installation?


* SMB encryption or signing not enforced

* NTLM/NTLMv1 enabled

* mDNS/llmnr/nbt-ns enabled

* dhcpv6 not controlled

* Privileged account doing plain LDAP (not LDAPS) binds or unencrypted FTP connections

* WPAD not controlled

* lights out interfaces not segregated from business network. Bonus points if its a supermicro which discloses the password hash to unauthenticated users as a design features.

* operational technology not segregated from information technology

* Not a windows bug, but popular on windows: 3rd party services with unquoted exe and uninstall strings, or service executable in a user-writable directory.

I remediate pentests as well as realworld intrusion events and we ALWAYS find one of these as the culprit. An oopsie happening on the public website leading to an intrusion is actually an extreme rarity. It's pretty much always email > standard user > administrator.

I understand not liking EDR or AV but the alternative seems to be just not detecting when this happens. The difference between EDR clients and non-EDR clients is that the non-EDR clients got compromised 2 years ago and only found it today.


Thanks for the list. I got this job as the network administrator at a community bank 2 years ago and 9/9 of these were on/enabled/not secured. I've got it down to only 3/9 (dhcpv6, unquoted exe, operational tech not segregated from info tech). I'm asking for free advise, so feel free to ignore me, but of these three unremediated vectors, which do you see as the culprit most often?


dhcpv6 poisoning is really easy to do with metasploit and creates a MITM scenario. It's also easy to fix (dhcpv6guard at the switch, a domain firewall rule, or a 'prefer ipv4' reg key).

unquoted paths are used to make persistence and are just an indicator of some other compromise. There are some very low impact scripts on github that can take care of it

Network segregation, the big thing I see in financial institutions is the cameras. Each one has its own shitty webserver, chances are the vendor is accessing the NVR with teamviewer and just leaving the computer logged in and unlocked, and none of the involved devices will see any kind of update unless they break. Although I've never had a pentester do anything with this I consider the segment to be haunted.


None of those things require a kernel module with remote code execution to configure properly.


I believe the question was 'in which ways is windows vulnerable by default', and I answered that.

If customers wanted to configure them properly, they could, but they don't. EDR will let them keep all the garbage they seem to love so dearly. It doesn't just check a box, it takes care of many other boxes too.


At work we have two sets of computers. One gets beamed down by our multi-national overlords, loaded with all kinds of compliance software. The other is managed by local IT and only uses windows defender, has some strict group policies applied, BMCs on a separate vlans etc. Both pass audits, for whatever that's worth.


This is the key question for me: is there a way to get [most of] the security benefits of EDR without giving away the keys to the kingdom.


No. If an EDR relies on userland mechanisms to monitor, these userland mechanisms can easily be removed by the malicious process too.


> It's pretty much always email > standard user > administrator

What does this mean?


believe it or not, most users dont run around downloading random screensavers or whatever. Instead they are receiving phish emails, often from trusted contacts who have recently been compromised using the same style of message that they are used to receiving, that give the attacker a foothold on the computer. From there, you can use a commonly available insecure legacy protocol or other privilege escalation technique to gain administrative rights on the device.


standard user: why can't I open this pdf? It says Permission Denied

dumb admin: let me try .... boom game over man


It's the attack path.


>> always email > standard user > administrator

maybe its the boomers that can't give up Outlook? Otherwise they could've migrated everybody to google workspaces or some other web alternative.


You don't need exploits to remotely access and run commands on other systems, steal admin passwords, and destroy data. All the tools to do that are built into Windows. A large part of why security teams like EDR is that it gives them the data to detect abuse of built-in tools and automatically intervene.


Not on a fully patched system. 0-days are relatively rare and fixed pretty quickly by Microsoft.


Remember WannaCry? The vuln it used was patched by MS two months prior the attack. Yet it took the world by storm.


Not sure what you want from me, I simply answered the question. Yes I remember WannaCry.


How is it caviar then?


Not the same poster, but one phase of a typical attack inside a corporate network is lateral movement. You find creds on one system and want to use them to log on to a second system. Often, these creds have administrative privileges on the second system. No vulnerabilities are necessary to perform lateral movement.

Just as an example: you use a mechanism similar to psexec to execute commands on the remote system using the SMB service. If the remote system has a capable EDR, it will shut that down and report the system from which the connection came from to the SOC, perhaps automatically isolate it. If it doesn't, an attacker moves laterally through your entire network with ease in no time until they have domain admin privs.


A key part of breach a network is having a beacon running on their networks, and communicating out, one way or another.

Running beacons with good EDRs is difficult, and has become the most challenging aspect of most red team engagements because of that.

No EDR, everything becomes suddenly super easy.




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