Tag: Active Directory

There’s Something About Service Accounts

Service accounts are that gray area between regular user accounts and admin accounts that are often highly privileged. They are almost always over-privileged due to documented vendor requirements or because of operational challenges (“just make it work”). We can discover service accounts by looking for user accounts with Kerberos Service Principal Names (SPNs) which I …

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From DNSAdmins to Domain Admin, When DNSAdmins is More than Just DNS Administration

It’s been almost 1.5 years since the Medium post by Shay Ber was published that explained how to execute a DLL as SYSTEM on a Domain Controller provided the account is a member of DNSAdmins. I finally got around to posting here since many I speak with aren’t aware of this issue. Shay describes this …

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BSides Charm (2017) Talk Slides Posted – Detecting the Elusive: Active Directory Threat Hunting

I recently presented my talk  “Detecting the Elusive: Active Directory Threat Hunting” at BSides Charm in Baltimore, MD. Slides are now posted in the Presentations section. I cover some of the information I’ve posted here before: PowerShell Security Detecting Kerberoasting: Part 1 and Part 2   On Sunday, April 30th, 2017, I spoke at BSides Charm in …

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Black Hat USA 2016 Talk – Beyond the MCSE: Active Directory for the Security Professional

This summer in Las Vegas, I’m speaking at Black Hat USA 2016 on Active Directory security, “Beyond the MCSE: Active Directory for the Security Professional.” This talk covers the key AD security components with specific focus on the things security professionals should know. I put this talk together because I have noticed that while Active …

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Kerberos, Active Directory’s Secret Decoder Ring

Kerberos Overview Kerberos is a protocol with roots in MIT named after the three-headed dog, Cerberus. Named because there are 3 parties: the client, the resource server, and a 3rd party (the Key Distribution Center, KDC). Kerberos can be a difficult authentication protocol to describe, so I will attempt to simplify it as best as …

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Removing an Orphan (inactive) Active Directory Domain

Removing an Orphan (inactive) Active Directory Domain One of my customers has a forest with several domains, one of which hasn’t been used in a while (call it domain “RedShirt”). The 2 Domain Controllers in the domain, “RedShirt” both tombstoned. Yes, I know, how does that happen? ALWAYS monitor your environment. Since the domain hasn’t …

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RODC Trick: Remove a User’s Password from a RODC without forcing the user to change her password

TechNet (RODC FAQ) states: How can you clear a password that is cached on an RODC? There is no mechanism to erase passwords after they are cached on an RODC. If you want to clear a password that is stored on an RODC, an administrator should reset the password in the hub site. This way, …

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Active Directory Security Group Resources

Laura Robinson (Microsoft) has 2 posts which are excellent resources when working on your Active Directory delegation model. These posts focus on the concept of an “Admin-Free Active Directory” meaning that there are no accounts in the powerful AD groups: Enterprise Admins, Domain Admins, Administrators, & Schema Admins. The posts also list all of the …

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