type: attack-pattern
spec_version: 2.1
id: attack-pattern--6b57dc31-b814-4a03-8706-28bc20d739c4
created: 2020-06-24T12:42:35.144Z
created_by_ref: identity--c78cb6e5-0c4b-4611-8297-d1b8b55e40b5
revoked: no
external_references: source_name: mitre-attack
url: https://attack.mitre.org/techniques/T1098/004
external_id: T1098.004
source_name: Venafi SSH Key Abuse
description: Blachman, Y. (2020, April 22). Growing Abuse of SSH Keys: Commodity Malware Campaigns Now Equipped with SSH Capabilities. Retrieved June 24, 2020.
url: https://www.venafi.com/blog/growing-abuse-ssh-keys-commodity-malware-campaigns-now-equipped-ssh-capabilities
source_name: Broadcom ESXi SSH
description: Broadcom. (2024, December 12). Allowing SSH access to VMware vSphere ESXi/ESX hosts with public/private key authentication. Retrieved March 26, 2025.
url: https://knowledge.broadcom.com/external/article/313767/allowing-ssh-access-to-vmware-vsphere-es.html
source_name: Google Cloud Privilege Escalation
description: Chris Moberly. (2020, February 12). Tutorial on privilege escalation and post exploitation tactics in Google Cloud Platform environments. Retrieved April 1, 2022.
url: https://about.gitlab.com/blog/2020/02/12/plundering-gcp-escalating-privileges-in-google-cloud-platform/
source_name: cisco_ip_ssh_pubkey_ch_cmd
description: Cisco. (2021, August 23). ip ssh pubkey-chain. Retrieved July 13, 2022.
url: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/security/d1/sec-d1-cr-book/sec-cr-i3.html#wp1254331478
source_name: Cybereason Linux Exim Worm
description: Cybereason Nocturnus. (2019, June 13). New Pervasive Worm Exploiting Linux Exim Server Vulnerability. Retrieved June 24, 2020.
url: https://www.cybereason.com/blog/new-pervasive-worm-exploiting-linux-exim-server-vulnerability
source_name: Google Cloud Add Metadata
description: Google Cloud. (2022, March 31). gcloud compute instances add-metadata. Retrieved April 1, 2022.
url: https://cloud.google.com/sdk/gcloud/reference/compute/instances/add-metadata
source_name: Azure Update Virtual Machines
description: Microsoft. (n.d.). Virtual Machines - Update. Retrieved April 1, 2022.
url: https://docs.microsoft.com/en-us/rest/api/compute/virtual-machines/update
source_name: SSH Authorized Keys
description: ssh.com. (n.d.). Authorized_keys File in SSH. Retrieved June 24, 2020.
url: https://www.ssh.com/ssh/authorized_keys/
object_marking_refs: marking-definition--fa42a846-8d90-4e51-bc29-71d5b4802168
modified: 2025-10-24T17:48:55.005Z
name: SSH Authorized Keys
description: Adversaries may modify the SSH authorized_keys file to maintain persistence on a victim host. Linux distributions, macOS, and ESXi hypervisors commonly use key-based authentication to secure the authentication process of SSH sessions for remote management. The authorized_keys file in SSH specifies the SSH keys that can be used for logging into the user account for which the file is configured. This file is usually found in the user's home directory under <user-home>/.ssh/authorized_keys (or, on ESXi, `/etc/ssh/keys-/authorized_keys`).(Citation: SSH Authorized Keys) Users may edit the system’s SSH config file to modify the directives `PubkeyAuthentication` and `RSAAuthentication` to the value `yes` to ensure public key and RSA authentication are enabled, as well as modify the directive `PermitRootLogin` to the value `yes` to enable root authentication via SSH.(Citation: Broadcom ESXi SSH) The SSH config file is usually located under /etc/ssh/sshd_config.

Adversaries may modify SSH authorized_keys files directly with scripts or shell commands to add their own adversary-supplied public keys. In cloud environments, adversaries may be able to modify the SSH authorized_keys file of a particular virtual machine via the command line interface or rest API. For example, by using the Google Cloud CLI’s “add-metadata” command an adversary may add SSH keys to a user account.(Citation: Google Cloud Add Metadata)(Citation: Google Cloud Privilege Escalation) Similarly, in Azure, an adversary may update the authorized_keys file of a virtual machine via a PATCH request to the API.(Citation: Azure Update Virtual Machines) This ensures that an adversary possessing the corresponding private key may log in as an existing user via SSH.(Citation: Venafi SSH Key Abuse)(Citation: Cybereason Linux Exim Worm) It may also lead to privilege escalation where the virtual machine or instance has distinct permissions from the requesting user.

Where authorized_keys files are modified via cloud APIs or command line interfaces, an adversary may achieve privilege escalation on the target virtual machine if they add a key to a higher-privileged user. 

SSH keys can also be added to accounts on network devices, such as with the `ip ssh pubkey-chain` [Network Device CLI](https://attack.mitre.org/techniques/T1059/008) command.(Citation: cisco_ip_ssh_pubkey_ch_cmd)
kill_chain_phases: kill_chain_name: mitre-attack
phase_name: persistence
kill_chain_name: mitre-attack
phase_name: privilege-escalation
x_mitre_attack_spec_version: 3.2.0
x_mitre_contributors: Tony Lambert, Red Canary
Dror Alon, Palo Alto Networks
Or Kliger, Palo Alto Networks
Austin Clark, @c2defense
Arad Inbar, Fidelis Security
x_mitre_deprecated: no
x_mitre_domains: enterprise-attack
x_mitre_is_subtechnique: yes
x_mitre_modified_by_ref: identity--c78cb6e5-0c4b-4611-8297-d1b8b55e40b5
x_mitre_platforms: Linux
macOS
IaaS
Network Devices
ESXi
x_mitre_version: 1.4