Query: Outbound C2 pattern associated with Exploitation of Remote Services
Matching passage: T1210 Exploitation of Remote Services. Tactics: lateral movement. Description: Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network. Exploitation of a software vulnerability occurs when an adversary takes advantage of a programming error in a program, service, or within the operating system software or kernel itself to execute adversary-controlled code. A common goal for post-compromise exploitation of remote services is for lateral movement to enable access to a remote system. An adversary may need to determine if the remote system is in a vulnerable state, which may be done through [Network Service Discovery](https://attack.mitre.org/techniques/T1046) or other Discovery methods looking for common, vulnerable software that may be deployed in the network, the lack of certain patches that may indicate vulnerabilities, or security software that may be used to detect or contain remote exploitation. Servers are likely a high value target for lateral movement exploitation, but endpoint systems may also be at risk if they provide an advantage or access to additional resources. There are several well-known vulnerabilities that exist in common services such as SMB(Citation: CIS Multiple SMB Vulnerabilities) and RDP(Citation: NVD CVE-2017-0176) as well as applications that may be used within internal networks such as MySQL(Citation: NVD CVE-2016-6662) and web server services.(Citation: NVD CVE-2014-7169)(Citation: Ars Technica VMWare Code Execution Vulnerability 2021) Additionally, there have been a number of vulnerabilities in VMware vCenter installations, which may enable threat actors to move laterally from the compromised vCenter server to virtual machines or even to ESXi hypervisors.(Citation: Broadcom VMSA-2024-0019) Depending on the permissions level of the vulnerable remote service an adversary may achieve [Exploitation for Privilege Escalation](https://attack.mitre.org/techniques/T1068) as a result of lateral movement exploitation as well.
Near-miss passage: T1021.004 SSH. Tactics: lateral movement. Description: Adversaries may use [Valid Accounts](https://attack.mitre.org/techniques/T1078) to log into remote machines using Secure Shell (SSH). The adversary may then perform actions as the logged-on user. SSH is a protocol that allows authorized users to open remote shells on other computers. Many Linux and macOS versions come with SSH installed by default, although typically disabled until the user enables it. On ESXi, SSH can be enabled either directly on the host (e.g., via `vim-cmd hostsvc/enable_ssh`) or via vCenter.(Citation: Sygnia ESXi Ransomware 2025)(Citation: TrendMicro ESXI Ransomware)(Citation: Sygnia Abyss Locker 2025) The SSH server can be configured to use standard password authentication or public-private keypairs in lieu of or in addition to a password. In this authentication scenario, the user’s public key must be in a special file on the computer running the server that lists which keypairs are allowed to login as that user (i.e., [SSH Authorized Keys](https://attack.mitre.org/techniques/T1098/004)).