Category: Technical Reference

PowerShell Version 5 Security Enhancements

PowerShell version 5 is RTM (As of 12/18/2015). Prior to this there was a “production preview” available since August which means it was supported, but not final. With the final release of PowerShell v5 now available, I highly recommend you download PowerShell v5 and start testing to prepare for production deployment. While the PowerShell v5 …

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How Attackers Dump Active Directory Database Credentials

I previously posted some information on dumping AD database credentials before in a couple of posts: “How Attackers Pull the Active Directory Database (NTDS.dit) from a Domain Controller” and “Attack Methods for Gaining Domain Admin Rights in Active Directory“. This post covers many different ways that an attacker can dump credentials from Active Directory, both …

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Attack Methods for Gaining Domain Admin Rights in Active Directory

There are many ways an attacker can gain Domain Admin rights in Active Directory. This post is meant to describe some of the more popular ones in current use. The techniques described here “assume breach” where an attacker already has a foothold on an internal system and has gained domain user credentials (aka post-exploitation). The …

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Cracking Kerberos TGS Tickets Using Kerberoast – Exploiting Kerberos to Compromise the Active Directory Domain

Microsoft’s Kerberos implementation in Active Directory has been targeted over the past couple of years by security researchers and attackers alike. The issues are primarily related to the legacy support in Kerberos when Active Directory was released in the year 2000 with Windows Server 2000. This legacy support is enabled when using Kerberos RC4 encryption …

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Finding Passwords in SYSVOL & Exploiting Group Policy Preferences

At Black Hat and DEF CON this year, I spoke about ways attackers go from Domain User to Domain Admin in modern enterprises. Every Windows computer has a built-in Administrator account with an associated password. Changing this password is a security requirement in most organizations, though the method for doing so is not straight-forward. A …

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Unofficial Guide to Mimikatz & Command Reference

A new page on ADSecurity.org just went live which is an “unofficial” guide to Mimikatz which also contains an expansive command reference of all available Mimikatz commands. Screenshots, descriptions, and parameters are included where available and appropriate. This page includes the following topics: Mimikatz Overview Mimikatz & Credentials Available Credentials by OS PowerShell & Mimikatz …

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Dump Clear-Text Passwords for All Admins in the Domain Using Mimikatz DCSync

The two key goals of any attack is access and persistence. This post covers elements of each. In a post-exploitation scenario where the attacker has compromised the domain or an account with delegated rights, it’s possible to dump the clear-text passwords of admins without being a Domain Admin*. This method requires the Active Directory Domain …

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How Attackers Use Kerberos Silver Tickets to Exploit Systems

Usually Golden Tickets (forged Kerberos TGTs) get all the press, but this post is about Silver Tickets and how attackers use them to exploit systems. I have talked about how Silver Tickets can be used to persist and even re-exploit an Active Directory enterprise in presentations at security conferences this year. This post continues this …

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The Most Common Active Directory Security Issues and What You Can Do to Fix Them

The past couple of years of meeting with customers is enlightening since every environment, though unique, often has the same issues. These issues often boil down to legacy management of the enterprise Microsoft platform going back a decade or more. I spoke about Active Directory attack and defense at several security conferences this year including …

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Sneaky Active Directory Persistence Tricks

The content in this post links to several methods through which an attacker could persist administrative access to Active Directory after having Domain Admin level rights for 5 minutes. While there are an infinite number of actions an attacker can perform after compromising an enterprise, there are a finite number of pathways. In this series, …

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