Last week, the CERT Coordination Center (CERT/CC) issued a vulnerability note warning versions of Microsoft Exchange 2013 and newer are vulnerable to an NTLM relay attack that allows for attackers to gain domain admin privileges. Organizations that rely on Microsoft Exchange are currently at risk of a serious data breach. This attack is particularly concerning given that it obtains privileges to the domain controller, which is essentially the “keys to the kingdom.” We’ve simplified some of the specifics of this attack for the purposes of this blog, but for a full technical breakdown, please see research from Dirk-jan Mollema.
It has been more than a year since I last shared Preempt Inspector statistics. Last time we shared Preempt Inspector statistics we found some alarming numbers. With the end of 2018 approaching, I would like to share with you key findings from Preempt Inspector [a free security tool available to download here] to help you focus on the most important security issues you might be facing.
NTLM (NT LAN Manager) is Microsoft's old authentication protocol that was replaced with Kerberos starting Windows 2000. It was designed and implemented by Microsoft engineers for the purpose of authenticating accounts between Microsoft Windows machines and servers. Even though it has not been the default for Windows deployments for more than 17 years, it is still very much in use, and I have not yet seen a network where it has been completely abandoned. In fact, it also supported by the latest version of Active Directory.
I was recently working with a large US-based company that suffered from repeated breaches to their corporate network. After we deployed the Preempt Platform and started monitoring all traffic, we quickly found several hacked privileged accounts that attackers were using. The interesting thing was that all privileged accounts were protected with password vaults and their passwords were rotated every 24 hours. In that particular case, the attackers compromised a web gateway that some admins logged into each day using a plaintext password. Using this weakness, attackers easily defeated the Privileged Access Management (PAM) solution, they simply had to harvest the password each day and do whatever they wanted with it.
Preventing lateral movement and unauthorized domain access due to the misuse of network credentials - especially due to reconnaissance tools looking for weak spots - is a challenge plaguing many enterprises. In fact, it’s a decades-old security problem. A major issue for enterprises has been how to detect and contain the use of reconnaissance tools like BloodHound, authentication protocols such as NTLM, DCE/RPC, Kerberos and Lightweight Directory Access Protocol (LDAP), as well as other IT tools like PsExec and Powershell that are being misused or exploited by attackers.
In March Patch Tuesday, Microsoft released a patch for CVE-2018-0886, a vulnerability discovered by Preempt researchers. The vulnerability consists of a logical flaw in Credential Security Support Provider protocol (CredSSP) which is used by RDP (Remote Desktop Protocol) and Windows Remote Management (WinRM) that takes care of securely forwarding credentials to target servers. The vulnerability can be exploited by attackers by employing a man-in-the-middle attack to achieve the ability to run code remotely on previously not infected machines in the attacked network. The vulnerability, in many real-world scenarios where victim network has vulnerable network equipment, could result in an attacker gaining the ability to move laterally in the victim’s network and even infect domain controller with malicious software. No attacks have been detected in the wild by Preempt.
Last month I attended Black Hat USA 2017 conference. It did not disappoint. Overall the event and packed agenda was well worth it. I enjoyed the vibe, the networking, the briefings, the business hall and the wonderful keynote by Alex Stamos (I recommend you follow Eran’s post who shared some of Alex’s deep insights). Overall the event covered a broad array of bleeding edge infosec topics with sessions on research, zero day exploits, open source tools, and other security risks and trends.
Over the past few months, the Preempt research team discovered and reported two Microsoft NT LAN Manager (NTLM) vulnerabilities. These vulnerabilities have a common theme around two different protocols handling NTLM improperly. These issues are particularly significant as they can potentially allow an attacker to create new domain administrator accounts even when best-practice controls such as LDAP server signing and RDP restricted admin mode are enabled.
NotPetya, a recent malware, masquerading as the known Petya ransomware started wreaking havoc at a world scale last week. Initially, it looked like another wave in the malware storm that started with Shadow Brokers’ publication of EternalBlue and other zero-day vulnerabilities in Windows OS. And, in fact, NotPetya used EternalBlue as one of the lateral movement methods in its arsenal. But, apparently, the developers of NotPetya wanted to hit some high-value targets and the risk that these networks had already been fully patched would have ruined their attack.
Recently, the new draft of NIST guidelines was released and proposed a shift in password strategy from periodic changes with complexity requirements to use of a long "memorized secret.” Many organizations have forced regular password changes and password complexity but this has failed them.