Yaron Zinar

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Recent Posts

New LDAP & RDP Relay Vulnerabilities in NTLM

Posted by Yaron Zinar on Jul 11, 2017 10:01:54 AM

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.

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Topics: Domain Controller, NTLM, Hacking, Threat Detection

How to Stop NotPetya and Similar Ransomware from Spreading in the Network

Posted by Yaron Zinar on Jul 5, 2017 2:06:01 PM

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.

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Topics: Adaptive Response, Credential Compromise, ueba, Ransomware

1 in 5 Enterprise Passwords Can Be Easily Compromised

Posted by Yaron Zinar on Jun 14, 2017 5:00:00 AM

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.

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Topics: CISO, Passwords

Real-time vs After the Fact: Pitfalls of Log-based Behavioral Threat Detection

Posted by Yaron Zinar on Apr 13, 2017 7:52:35 AM

It was recently published that Shadow Brokers, the group behind the Equation Group leak, are selling a new set of tools that have the ability to tamper with Windows event logs. What stood out to me is the inefficiency of security solutions that rely solely on logs for detecting threats. Implementing a security analytics or a UEBA product that relies on logs for detection of advanced cyber threats has advantages, but it is also risky.

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Topics: APT, User and Entity Behavior Analytics, Threat Detection

Kerberos, NTLM and SAM: 3 Ways Attackers Can Crack Passwords

Posted by Yaron Zinar on Mar 23, 2017 9:25:12 AM

In a previous blog, we discussed the prevalence of weak passwords in the Enterprise. The fact of the matter is, once an attacker gains access to password challenges and exfiltrates them for offline cracking, they can crack them in most cases.

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Topics: NTLM, kerberos, Passwords, SAM

The Security Risks of NTLM: Proceed with Caution

Posted by Yaron Zinar on Oct 20, 2016 3:05:29 PM

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 15 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.

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Topics: Risk, Active Directory, NTLM, kerberos

Do Smart Cards Protect You From Credential Theft?

Posted by Yaron Zinar on Aug 11, 2016 7:07:18 AM

In recent years, the use of smart card widely increased as a secure form of authentication for a wide range of applications, ranging from mobile networks requiring a SIM card in mobile devices to credit card vendors making smart cards, the de facto standard for credit cards.

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Topics: Smart Card, Active Directory

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