T1562.010 - Downgrade Attack

Adversaries may downgrade or use a version of system features that may be outdated, vulnerable, and/or does not support updated security controls. Downgrade attacks typically take advantage of a system’s backward compatibility to force it into less secure modes of operation.

Adversaries may downgrade and use various less-secure versions of features of a system, such as Command and Scripting Interpreters or even network protocols that can be abused to enable Adversary-in-the-Middle or Network Sniffing.(Citation: Praetorian TLS Downgrade Attack 2014) For example, PowerShell versions 5+ includes Script Block Logging (SBL) which can record executed script content. However, adversaries may attempt to execute a previous version of PowerShell that does not support SBL with the intent to Impair Defenses while running malicious scripts that may have otherwise been detected.(Citation: CrowdStrike BGH Ransomware 2021)(Citation: Mandiant BYOL 2018)(Citation: att_def_ps_logging)

Adversaries may similarly target network traffic to downgrade from an encrypted HTTPS connection to an unsecured HTTP connection that exposes network data in clear text.(Citation: Targeted SSL Stripping Attacks Are Real)(Citation: Crowdstrike Downgrade)

Atomic Tests:

Currently, no tests are available for this technique.

Detection

Monitor for commands or other activity that may be indicative of attempts to abuse older or deprecated technologies (ex: powershell –v 2). Also monitor for other abnormal events, such as execution of and/or processes spawning from a version of a tool that is not expected in the environment.

Monitor for Windows event ID (EID) 400, specifically the EngineVersion field which shows the version of PowerShell running and may highlight a malicious downgrade attack.(Citation: inv_ps_attacks)

Monitor network data to detect cases where HTTP is used instead of HTTPS.