I originally wrote this for work, where we get a lot of requests to “Red Team” something. In a lot of these cases, a white box security review or other form of security testing is more appropriate. Because I’d heard through the grapevine that other Red Teams struggle with the same issues, I wanted to make it available publicly. Thanks to my management for their support and permission to take this public!

If you’d like to use or adapt this within your organization, feel free, but please give credit to the Google Red Team.

We frequently get requests to perform Red Team engagements on various products & services around our company. These requests often have misconceptions about the services our team provides. This document is intended to help those seeking a Red Team engagement have a better understanding of what we do, how we do it, and why we do it the way we do, and how to engage with us for optimal effectiveness.

What is a Red Team Exercise?

A Red Team Exercise is a goal-oriented simulation of an attacker targeting a part of our company. Within the constraints of our resources and rules of engagement, we attempt to:

  • Emulate what real adversaries would do, with the purpose of testing our security controls and detection and response capabilities
  • Evaluate mechanisms attackers use to move laterally
  • Increase security awareness

We focus on realistic scenarios based on our understanding of the attacker landscape and capabilities.

What does Goal-Oriented Mean?

In conjunction with our threat intelligence and incident response teams, and security advocates from around the company, we identify particular data or systems that a real world attacker would want to gain access to and could feasibly attack successfully.

Note: Our focus (like an attacker’s) is on the end goal and we will simulate the most likely attack path to that goal. This means that if we can meet our objective by stealing backups and never touching the service that generated that data, we may approach it via that attack path. Attackers will follow the easiest path within their risk tolerance of being discovered in order to meet their objectives. This means that some vulnerabilities, systems, and processes are not good candidates for a Red Team exercise simply because real world attackers are unlikely to progress via that path when easier or lower risk paths exist.

How does a Red Team compare to a Security Review or a Penetration Test?

A Red Team is complementary to a Security Review – one does not substitute the other. Penetration tests are a sort of middle ground where vulnerabilities are enumerated and tested, but generally without regard to attacker intent and objective. We do not currently conduct such penetration tests, as they don’t help us achieve our goal or mission.

  Security Review Penetration Test Red Team
Primary Goal Review a single product/service in isolation to look for security bugs, weaknesses, or opportunities for hardening. Attempt to identify and address as many weaknesses as possible. Attempt to enumerate vulnerabilities and potentially test the exploitability of them. Achieve a particular goal in the same manner that an attacker would. Only attempt to identify weaknesses that further the attacker’s goals.
Level of Knowledge White-box and transparent – a security reviewer should have access to the source, documentation, etc. Usually black box, but some insider knowledge may be used. Attempts to only use information available to an attacker.
Scope Single product/service. Varies Org-wide to get to the target/objective.

What does Adversary Emulation Mean?

We attempt to use the same Tactics, Tools, and Procedures (TTPs) that are available to our attackers. We don’t always emulate the same attacker model – sometimes we look at insider threats, sometimes it’s nation-state adversaries, and sometimes it’s cybercrime groups. In each case, we endeavor to use only the resources and TTPs that would be available to that attacker.

We simulate each part of the attack as though our company were actually getting hacked:

  • Reconnaissance: Gather information about the target from the internet
  • Infiltration: Test and exploit systems or send phishing campaigns
  • Lateral Movement: Move laterally through the network
  • Exfiltration: Gather real or simulated “loot”, including corporate and user data.

Using this approach of simulating the entire attack makes the exercise a real test of our controls, which has multiple benefits, including:

  • Testing detection and response systems and processes against actual attacks
  • Demonstrating the impact of an attack to leadership
  • Helping prioritize the vulnerabilities or issues to tackle, depending on which are most beneficial to attackers

Preparing for a Red Team

If you feel a Red Team is appropriate for your concerns, please review the considerations below and provide the requested information.

Have you had a Security Review?

We strongly recommend having undergone a Security Review before a Red Team. Security Reviews are scoped to the single service rather than the larger ecosystem, will try to find a breadth of issues instead of going deep into a small number of issues, and can help inform the threat model for the Red Team.

Planning the Engagement – Threat Model

Consider the following questions when requesting a Red Team engagement. Your answers help us figure out the optimal plan for the engagement.

  1. What data or access is the adversary hoping to acquire? This helps us determine the objective.
  2. Who is going to be attacking us? Is it an insider, cyber criminals, nation state adversaries, etc.?
  3. What resources are they willing to use for this exercise? Is it worth the use of 0-day exploits, or just basic phishing?
  4. What other products or services might an attacker consider to get to the same outcome?
  5. What is the impact to our company of an attacker gaining this access?