Modify Cloud Compute Infrastructure: Revert Cloud Instance

An adversary may revert changes made to a cloud instance after they have performed malicious activities in attempt to evade detection and remove evidence of their presence. In highly virtualized environments, such as cloud-based infrastructure, this may be accomplished by restoring virtual machine (VM) or data storage snapshots through the cloud management dashboard or cloud APIs.

Another variation of this technique is to utilize temporary storage attached to the compute instance. Most cloud providers provide various types of storage including persistent, local, and/or ephemeral, with the ephemeral types often reset upon stop/restart of the VM.[1][2]

ID: T1578.004
Sub-technique of:  T1578
Tactic: Defense Evasion
Platforms: IaaS
Permissions Required: User
Contributors: Netskope
Version: 1.1
Created: 16 June 2020
Last Modified: 08 March 2021

Mitigations

This type of attack technique cannot be easily mitigated with preventive controls since it is based on the abuse of system features.

Detection

ID Data Source Data Component Detects
DS0030 Instance Instance Metadata

Periodically baseline instances to identify malicious modifications or additions.

Instance Modification

Establish centralized logging of instance activity, which can be used to monitor and review system events even after reverting to a snapshot, rolling back changes, or changing persistence/type of storage. Monitor specifically for events related to snapshots and rollbacks and VM configuration changes, that are occurring outside of normal activity. To reduce false positives, valid change management procedures could introduce a known identifier that is logged with the change (e.g., tag or header) if supported by the cloud provider, to help distinguish valid, expected actions from malicious ones.

Instance Start

Establish centralized logging of instance activity, which can be used to monitor and review system events even after reverting to a snapshot, rolling back changes, or changing persistence/type of storage. Monitor specifically for events related to activation of instances that are occurring outside of normal activity/planned operations. To reduce false positives, valid change management procedures could introduce a known identifier that is logged with the change (e.g., tag or header) if supported by the cloud provider, to help distinguish valid, expected actions from malicious ones.

Instance Stop

Establish centralized logging of instance activity, which can be used to monitor and review system events even after reverting to a snapshot, rolling back changes, or changing persistence/type of storage. Monitor specifically for events related to deactivation of instances that are occurring outside of planned operations. To reduce false positives, valid change management procedures could introduce a known identifier that is logged with the change (e.g., tag or header) if supported by the cloud provider, to help distinguish valid, expected actions from malicious ones.

References