Quick answer: Virtual machine forensics is the process of collecting and examining the evidence of a security incident through virtual servers, snapshot files and the hypervisor layer. A virtual environment offers both an advantage and a challenge compared to a physical server: a snapshot can hold the complete state of the machine at a specific moment, even its memory content, which is a valuable time capsule for forensics. But virtual machines can be easily deleted, moved and altered, so the evidence can be short lived. The correct approach is to first preserve the running machine's memory and state, fix the integrity of the snapshot and disk files, then collect the hypervisor logs; all done without altering the original and with a chain of custody.

Servers now largely run in virtualized environments. This opens new evidence sources in an incident examination but also increases the volatility and complexity of the evidence. This article explains what is examined in virtual machine and snapshot forensics and how the correct process works.

Why virtual machine forensics is different

On a physical server the disk is fixed and examined directly. In a virtual environment the situation differs:

  • Snapshot advantage. A snapshot holds the machine's state at a specific moment, sometimes together with memory content. This is a valuable source for returning to the moment of the incident.
  • Volatility. A virtual machine can be easily deleted, moved or reset. Evidence can vanish faster than on a physical disk.
  • Hypervisor layer. The hypervisor under the virtual machines produces its own logs and configuration; this is a separate evidence source.
  • Memory snapshot. When a snapshot contains memory, running processes and network state can also be examined, making usually volatile data persistent.

Evidence sources and collection order

Layer Example evidence Volatility
Running virtual machine Live memory, processes, network Very high, first
Snapshot Disk and memory state of a moment Deletable, fix fast
Virtual disk Disk image file Medium, examine as an image
Hypervisor Management logs, configuration Can change, collect
Storage Snapshot history, deleted files Depends

If the snapshot contains memory, memory and RAM analysis can be done directly on this snapshot; this is a powerful way to examine volatile data without touching the live machine.

Snapshot, the time capsule of forensics

A snapshot holds the complete state of the virtual machine at a specific moment. This is a unique advantage for forensics: if a snapshot taken before or during the incident exists, that moment can be returned to. A deleted file, a closed process or a network connection open at that moment can still sit inside the snapshot. So in an incident examination the existing snapshot history is among the first sources to query.

The correct examination process

1. Preserve the running machine and memory

The suspect virtual machine must be isolated without deletion or reset, and its live memory and state captured with a snapshot or memory dump. Once this volatile data is lost it does not come back.

2. Fix snapshot and disk integrity

The integrity of the snapshot and virtual disk files must be fixed with a checksum and all examination done on copies. The original files are preserved according to digital evidence and chain of custody principles.

3. Examine the virtual disk as an image

The virtual disk file is treated like a forensic image and the file system is analyzed. Deleted files and a timeline are extracted. If a recovery dimension is needed, virtual machine disk image recovery methods also come into play.

4. Hypervisor and storage layer

Hypervisor logs, management operations and snapshot history are collected. In a cloud environment the cloud security and shared responsibility model determines which layer is whose responsibility.

The KAOS and DSET approach

DSET runs virtual machine and snapshot examination with a process that combines AI speed with human expert oversight. The local AI engine KAOS scans large volume virtual disk and log data for fast triage and anomaly detection, but every finding with evidentiary value is verified with expert oversight and a chain of custody. Because KAOS runs fully offline, sensitive virtual machine images are not sent to external services, which matters for privacy and KVKK. The result is a court admissible, repeatable examination report.

Frequently asked questions

If a snapshot is deleted, can it be recovered? It depends. A deleted snapshot can still be partially present in the storage layer and recovered with data recovery methods. The earlier and the more write free the response, the higher the odds.

Why is a snapshot with memory valuable? Because running processes, open network connections and data held in memory such as passwords are usually lost when the machine is shut down. A snapshot with memory freezes this volatile data at a specific moment and makes it persistent, which is a powerful source for examination.

In a cloud virtual machine, whose responsibility is the evidence? It depends on the shared responsibility model. Hypervisor and infrastructure logs are usually under the cloud provider's control, while the inside of the virtual machine and configuration are the customer's responsibility. The process must consider this distinction.

Sources

For the forensic examination of a security incident in your virtual machine, snapshot and hypervisor environment, contact DSET. We provide ISO/IEC 27037 compliant, court admissible examination from our Ankara Hacettepe Teknokent laboratory.