IT Forensics · macOS

Forensic analysis of macOS SSH – Investigating remote login and key traces

macOS can enable SSH access to a Mac via the „Remote Login“ feature. Furthermore, a Mac can itself be used as an SSH client. As a result, both server-side configurations and user-related client artefacts such as keys, configuration files or known hosts may be of forensic relevance.

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The presence of an SSH key or a known host does not automatically prove that a connection took place during the period under investigation. The configuration, trust relationship and actual session must be assessed separately.

Why LanCologne?

Since its foundation, LanCologne has specialised in professional IT forensics. Our staff have decades of experience in the field of information technology and assist companies, solicitors, private individuals and, on a regular basis, the courts in the technical investigation of complex digital matters.

The examination is, as a matter of principle, carried out exclusively on a forensic copy, a forensic image or a data source captured in a technically equivalent manner that preserves the integrity of the evidence. The original evidence remains unchanged and is stored in a manner that preserves its integrity.

Our services

We examine SSH-related system and user artefacts, including existing configurations, key material metadata, known hosts and – where available – logged remote login events. Private keys are handled in a way that preserves the integrity of the evidence and are not used unnecessarily.

Connection claims are correlated with unified logs, network and login artefacts.

Typical areas of application

Investigation into potential remote access
Incident Response and Breach Analysis
Checking SSH keys and configurations
Analysis of well-known remote systems
Reconstruction of remote administrative access
Correlation with login and network events
Judicial and non-judicial expert reports

This is how the forensic investigation is carried out

Once the backup has been completed, server-side and client-side SSH configurations are examined separately. User-specific .ssh directories are catalogued, relevant files are hashed, and the analysis is carried out exclusively on working copies.

Additional logs and network traces are used to verify the timing of actual sessions. A mere key or host entry is not regarded as proof of a session.

Why is this area of investigation relevant to forensics?

SSH can be a legitimate administration channel or part of unauthorised remote access. It is therefore particularly important to make a clear technical distinction between enabled functions, available means of access and connections that can actually be verified.

In incident response scenarios, correlating login, shell and network traces can reconstruct remote activity with much greater precision.

Frequently Asked Questions

Can macOS allow SSH access?+
Yes. SSH access to a Mac can be enabled via Remote Login.
Does an entry in `known_hosts` indicate a current connection?+
No. It initially displays a saved host reference and may date from an earlier period.
Does an existing SSH key prove that it has been used?+
No. Additional supporting documents are required for usage and specific sessions.
Are SSH artefacts relevant to incident response?+
Yes. They can provide important contextual information when investigating legitimate or unauthorised remote access attempts.

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LanCologne – macOS Forensics in Cologne

Do you need a professional analysis of SSH and remote login traces on a Mac? LanCologne can assist you with the collection of evidence that meets legal standards and technical reconstruction.

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