Slack Message Scanning
Connect Slack to Cremit Argus to scan public channels, private channels, and DMs for credentials pasted during debugging or ops discussions.
About this guide
This comprehensive guide will walk you through the complete setup process. Expected completion time: 5-10 minutes.
Overview
Argus's Slack message scanning reads channel messages, thread replies, and file uploads for credentials that get pasted during debugging or ops discussions. Installed as a Slack app; scope can be limited to public channels only or expanded to private channels where the app is invited.
Prerequisites
- Slack workspace Owner or Admin
- Permission to install and approve OAuth apps (or pre-approval from a workspace admin)
- A Cremit Argus account
Step-by-Step Setup
Step 1: Start the Slack install from Argus
- In Argus, go to Configuration > Scan Sources and click New
- Select Slack as the source type
- Click Install to Slack
Step 2: Approve the app in your workspace
Slack's OAuth consent screen opens.
- Review the requested scopes: channels:read, channels:history, files:read, and optionally groups:history for private channels
- Select the workspace where Argus should be installed
- Click Allow; you will be redirected back to Argus
Step 3: Choose channel scope
Decide what Argus can scan.
- Public channels: all public channels in the workspace, auto-included
- Private channels: only ones where Argus is explicitly invited (use /invite @Cremit Argus)
- DMs: not scanned by default; enabling requires additional workspace-admin consent
Step 4: Run the initial historical scan
Argus walks channel history up to the retention limit of your Slack plan.
- Progress is visible per channel on the source detail page
- Real-time scanning kicks in once history is caught up
Verification
To confirm the integration is configured correctly:
- The Slack source shows Connected and lists the expected channel count
- Recently sent test messages containing a dummy token are flagged within 1-2 minutes
- Private channels where you invited the Argus app appear in the target list
- No 'missing_scope' errors in the source's activity log
Troubleshooting
Issue: Private channels are missing from the list.
- Solution: The Argus app must be explicitly invited with /invite @Cremit Argus in each private channel. This is a Slack requirement, not an Argus limitation.
Issue: Historical scan stops partway through a channel.
- Solution: Slack's free plan limits message history visibility. Paid plans or Enterprise Grid remove this limit. Check the channel's banner for a retention notice.
Key Benefits
- Catches the paste-debugging pattern that escapes code scanners entirely
- Real-time scanning means exposures surface within minutes, not on the next weekly review
- Granular scope: public only, public + invited private, or full coverage via admin approval
- File upload scanning catches secrets in uploaded logs and env files