While I am at it anyway; #Phishing meets #SMB: Exploiting network trust to capture #NTLM hashes (#pentesting fun)

One effective phishing method leverages SMB connections to capture #NetNTLM hashes for offline #cracking, providing attackers with credentials for the next phase (for example social engineering or other tech attacks). Oh; BIT B.V. (bit.nl) did send my a set of abuse mails, … sorry 😆 … but very nice and thx 🙏🏼, anyway;

Exploit Path: Initial Phishing Vector: The attack starts with a phishing email or download website or something something, containing a payload (e.g., a malicious document or shortcut file, whatever, choose your poison).

The payload initiates an SMB request to the attacker-controlled server (`\\<C2IP>\share`), tricking the victim’s system into authenticating with it. Modern browsers like edge won’t fly; you need to get a bit more creative to execute this and no it’s not a hyperlink. Think Java. Or macro (although; meh).

Then we have SMB Request Redirection: Tools like Responder on the attacker’s C2 server capture NetNTLMv2 hashes during these authentication attempts. This works over IPv4 and IPv6, with IPv6 often prioritized in networks and less monitored. Hence #mitm6. But that’s another story.

Captured hashes are cracked offline using tools like #Hashcat, potentially giving credentials for further attacks. It’s also an excuse for my new RTX 5090 card. 😉

Observations from recent penetration tests where I executed this attack;

-Firewall Rules: not excisting … at all. 🥹
Many environments have outbound 'any-any' rules on firewalls, even on critical nets like Citrix farms. This unrestricted outbound traffic allows SMB authentication requests to reach attacker-controlled servers on the internet. And there is something with remote workers and open internet access lately…
-#Azure and #2FA Gaps, here we go again (see https://lnkd.in/g2ctMEDG); 2FA exclusions are another common issue:
- Trusted locations (e.g., `192.168.x.x` or specific IP ranges) configured to bypass 2FA/MFA.. intended to improve usability, such exclusions can be exploited once an attacker gains access to these "trusted" locations; simply put a VM inside a 192.168 range and chances are…. Good.

These misconfigurations reduce the effectiveness of otherwise robust security measures like MFA and firewall segmentation, giving attackers unnecessary opportunities.

The Takeaway: Attackers thrive on overlooked gaps in configuration. Whether it's outbound "any-any" firewall rules or MFA bypasses for trusted locations, these lapses provide unnecessary pathways for compromise. By combining phishing, SMB exploitation, and tools like Responder, we can target foundational weaknesses in even hybrid environments. I’ve seen soc’s only respond after mission target; because most are monitoring just on the endpoint (EDR/XDR), poorly.

#CyberSecurity #Phishing #SMB #NTLM #MFA #FirewallSecurity #infosec

The meme is absolutely intended as shitposting. Sorry 🤣

Henk-Jan Angerman on LinkedIn: #aitm #entra #mfa #entraid #2fa #microsoft #microsoft #entra #metaverse…

Combining a good write up in #aitm and #entra and recent real-world-attack scenarios. Moving forward on my previous post tabout legacy #MFA (debatable, again……

One example why to use strong #passwords for users who use file sharing over #SMB even when the file transfers are #encrypted.
If the SMB traffic is captured/eavesdropped, then the attacker can try to crack the user password.
The attacker is able to extract challenge/response values from the Session Setup and then use #passwordcracking tools such as #hashcat

If the attack is successful, the attacker will gain not only the access to the user account, but it is also possible to decrypt the captured SMB file transfers. There is lack of perfect forward secrecy in this encryption.

For more details and practical examples, see this blog post:

https://malwarelab.eu/posts/tryhackme-smb-decryption/

#networktrafficanalysis #networktraffic #encryption #netntlmv2 #netntlm #ntlm #windows #fileshare #pentesting #cybersecurity #hardening #password #cracking #offensivesecurity #offsec #blueteam #purpleteam

SMB Decryption - TryHackMe :: MWLab — Ladislav's Malware Lab

Recent TryHackMe room called “Block” inspired me to create this write-up. The task is to decrypt SMB3-encrypted communication. It turned out that sometimes we only need the captured network traffic to fulfill this task, while otherwise we need some additional info, such as user’s password or its NTLM hash. In this blog post, I would like to summarize three different approaches with practical hands-on exercises based on TryHackMe challenge. I will demonstrate methods of SMB decryption with the knowledge of the user’s password, its NTLM hash, and without any password/hash, just from the captured traffic only.

SMB Decryption - TryHackMe

A New #PyRDP Release: The Rudolph Desktop Protocol!

“The headline feature for this release is the ability to capture #NetNTLM hashes on any connection we can intercept.
[…] The potential certificate error is never displayed to the user. Certificate validation happens after the NetNTLM exchange under RDP’s Network Level Authentication (NLA) which is why it is never displayed. We reported this issue to Microsoft and they told us it works as designed.”

https://www.gosecure.net/blog/2022/12/23/a-new-pyrdp-release-the-rudolph-desktop-protocol/

A New PyRDP Release: The Rudolph Desktop Protocol! - GoSecure

Isn’t there a better moment than the Holiday season to release a major update of our RDP Attack and Eavesdropping tool PyRDP? That’s right, pour yourself a little glass of eggnog, sit in a comfortable chair, put on some Christmas music and read about the PyRDP updates by the fire.

GoSecure