T1557 Adversary-in-the-Middle

T1557 Adversary-in-the-Middle

High-Level Description

Adversaries may attempt to position themselves between two or more networked devices using an adversary-in-the-middle (AiTM) technique to support follow-on behaviors such as Network Sniffing, Transmitted Data Manipulation, or replay attacks (Exploitation for Credential Access). By abusing features of common networking protocols that can determine the flow of network traffic (e.g. ARP, DNS, LLMNR, etc.), adversaries may force a device to communicate through an adversary controlled system so they can collect information or perform additional actions.

For example, adversaries may manipulate victim DNS settings to enable other malicious activities such as preventing/redirecting users from accessing legitimate sites and/or pushing additional malware. Adversaries may also manipulate DNS and leverage their position in order to intercept user credentials, including access tokens (Steal Application Access Token) and session cookies (Steal Web Session Cookie). Downgrade Attacks can also be used to establish an AiTM position, such as by negotiating a less secure, deprecated, or weaker version of communication protocol (SSL/TLS) or encryption algorithm.

Adversaries may also leverage the AiTM position to attempt to monitor and/or modify traffic, such as in Transmitted Data Manipulation. Adversaries can setup a position similar to AiTM to prevent traffic from flowing to the appropriate destination, potentially to Impair Defenses and/or in support of a Network Denial of Service.

Kill Chain Phase

• Credential Access (TA0006)
• Collection (TA0009)

Platforms: Linux, macOS, Network Devices, Windows

What to Check

• Identify if Adversary-in-the-Middle technique is applicable to target environment
• Check Linux systems for indicators of Adversary-in-the-Middle
• Check macOS systems for indicators of Adversary-in-the-Middle
• Check Network Devices systems for indicators of Adversary-in-the-Middle
• Verify mitigations are bypassed or absent (7 known mitigations)
• Assess detection coverage (1 detection strategies)

How to Test

Manual Testing

1. Identify Attack Surface: Determine if the target environment is susceptible to Adversary-in-the-Middle by examining the target platforms (Linux, macOS, Network Devices).

2. Assess Existing Defenses: Review whether mitigations for T1557 are in place. If defenses are absent or misconfigured, this technique may be exploitable.

3. Execute Test: Use tools and methods described in the MITRE ATT&CK page and external references below.

Note: No Atomic Red Team tests available for this technique. See Atomic Red Team GitHub for updates.

Remediation Guide