Retrohunt with YARA rules

Learn how how to configure, execute, and interpret YARA retrohunts.

Retrohunting allows you to run a YARA rule against historical telemetry collected by Validin’s virtual host dataset.

This enables analysts to uncover older matches, validate rule effectiveness, and reconstruct activity that may no longer appear in live traffic.

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When to use retrohunting

Retrohunting is valuable when:

  • A rule was created after an incident began, and you need to identify earlier matches
  • Infrastructure has been taken offline and no longer appears in All Matches
  • You want to validate rule quality across a broader dataset
  • Comparing behaviour across multiple rule versions

Execute a retrohunt

Each YARA rule includes a dedicated retrohunt workflow.

To open a configuration modal, where all retrohunt parameters are defined:

  1. Open a Project.
  2. Select the YARA Rules tab.
  3. Select the rule you wish to investigate.
  4. Click New Retro in the information panel on the right.

1. Choose a rule version

Validin stores every saved version of a YARA rule. Retrohunts can be executed against any previous version using the Rule Version selector.

Only the selected version is executed during the hunt.

2. Set a lookback period

The Lookback selector determines how far back in time Validin should search.

Options include:

  • 1 Hour
  • 1 Day
  • 1 Week
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Lookback usage

Higher lookbacks cover more telemetry but increase data volume and API cost once billing is active.

The modal displays a Run Summary based on your chosen lookback period, including:

  • Estimated data volume to be scanned
  • Start and end timestamps of the lookback window
  • Expected query usage

3. Select a data type

The Type field controls which dataset the rule will scan. Currently available:

  • HTML Responses: Executes the rule against returned page content collected by Validin.
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YARA data types

Additional data types will appear as the platform evolves.

4. Configure completion notifications

Choose how to be notified when the retrohunt completes:

  • None
  • Alert (in-platform)
  • Alert and Email

5. Run the retrohunt

After setting configuration parameters:

  1. Select Run.
  2. The retrohunt begins processing historical data.
  3. You will be notified according to the configured completion option.

Retrohunt progress and past executions are tracked within the History tab for each rule.

View previous retrohunt runs

All completed retrohunts are visible under the rule’s History tab.

Each run includes:

  • Status
  • Completion time
  • Lookback range
  • Initiating user
  • Rule version used

Runs can be expanded or collapsed to manage long histories.

Selecting a completed run loads its full match output in the familiar results-table layout used by All Matches.

Using retrohunt results

Retrohunt results follow the same schema as live match results:

FieldDescription
Host/IPHost or resolved IP where a match was observed historically.
PortDestination port for the captured response.
Response/PathURL or resource where the match occurred.
TitleParsed HTML title of the returned document.
Bytes ReceivedSize of the archived HTTP response.
First SeenEarliest historical observation in the lookback window.
Last SeenMost recent observation within the retrohunt range.
Last Match TimeTimestamp of rule match within historical data.
CountNumber of times the matched resource appeared.

Retrohunt status and completion panel

When a retrohunt is running or has recently completed, a status panel appears in the rule sidebar that summarizes execution details, and provides visibility into progress and resource usage.

The panel includes the following information:

FieldDescription
Run TimeThe total amount of time the retrohunt has been executing or took to complete.
Lookback DurationThe historical window scanned (such as 1 hour or 1 week).
Lookback StartThe timestamp at which the lookback window begins.
Lookback EndThe timestamp at which the lookback window ends.
SourceThe dataset used, such as virtual host responses.
Progress BarIndicates execution progress in real time.

If a retrohunt is still in progress, a status bar and a Cancel button is displayed, allowing the user to track and terminate the request.

Retrohunt completion panel

Once the retrohunt completes, results become available in the History tab, grouped under the specific retrohunt run.

Comparing retrohunt and live results

Retrohunting highlights matches that may no longer appear in All Matches, including:

  • Decommissioned servers
  • Expired domains
  • Removed malicious content

Together with live results, this provides a full historical and real-time picture of adversary behaviour.


What’s Next