T1481.001_dead-drop-resolver

T1481.001 Dead Drop Resolver

Sub-technique of: T1481

High-Level Description

Adversaries may use an existing, legitimate external Web service to host information that points to additional command and control (C2) infrastructure. Adversaries may post content, known as a dead drop resolver, on Web services with embedded (and often obfuscated/encoded) domains or IP addresses. Once infected, victims will reach out to and be redirected by these resolvers.

Popular websites and social media, acting as a mechanism for C2, may give a significant amount of cover. This is due to the likelihood that hosts within a network are already communicating with them prior to a compromise. Using common services, such as those offered by Google or Twitter, makes it easier for adversaries to hide in expected noise. Web service providers commonly use SSL/TLS encryption, giving adversaries an added level of protection.

Use of a dead drop resolver may also protect back-end C2 infrastructure from discovery through malware binary analysis, or enable operational resiliency (since this infrastructure may be dynamically changed).

Kill Chain Phase

• Command and Control (TA0037)

Platforms: Android, iOS

What to Check

• Identify if Dead Drop Resolver technique is applicable to target mobile environment
• Check Android devices for indicators of Dead Drop Resolver
• Check iOS devices for indicators of Dead Drop Resolver
• Assess detection coverage (1 detection strategies)

How to Test

Identify Attack Surface

Determine if the target mobile environment is susceptible to Dead Drop Resolver by examining the target platforms (Android, iOS).

Assess Existing Defenses

Review whether mitigations for T1481.001 are in place. If defenses are absent or misconfigured, this technique may be exploitable.

Remediation Guide

No specific mitigations documented for this technique.

Detection

Detection of Dead Drop Resolver

Risk Assessment

CWE Categories

References

• MITRE ATT&CK Mobile - T1481.001