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Introduction:
A new, sophisticated phishing campaign is targeting software developers directly within their GitHub workflow. Attackers are exploiting the trust and notification mechanisms of pull requests (PRs) to deliver fraudulent messages impersonating legitimate organizations like Y Combinator and Gitcoin. This evolution of social engineering poses a significant threat to software supply chain security, bypassing traditional email filters by operating within a trusted development platform.
Learning Objectives:
- Understand the mechanics of the GitHub PR-based phishing campaign and how to identify its hallmarks.
- Learn immediate defensive commands and configurations to secure your GitHub account and notifications.
- Implement advanced monitoring and automation to detect and report malicious PR activity proactively.
You Should Know:
1. Analyzing Suspicious PR Metadata with GitHub CLI
The GitHub Command Line Interface (GH CLI) allows you to quickly fetch detailed information about a pull request, even after it’s been closed or the repository has been deleted from your local terminal. This is crucial for forensic analysis.
`gh pr view –repo –json url,title,author,comments,state,closed`
`gh api -X GET repos///pulls/`
`git log –all –grep=”github-verification” –oneline`
Step-by-step guide:
First, install the GH CLI. On Linux/macOS: brew install gh. On Windows: winget install GitHub.cli. Authenticate with gh auth login. If you are tagged in a suspicious PR, immediately use the first command to extract a snapshot of its JSON metadata, including the author’s login. The second command uses the GitHub API directly for more granular data. The third Git command scans your local repository’s log for mentions of known malicious domains embedded in commit messages.
2. Hardening Your GitHub Notification Settings
Reduce your attack surface by configuring your GitHub notification settings to limit exposure from unsolicited PR mentions. This is a primary mitigation step.
`gh api -X PATCH user –field notification_email_restrictions=true`
Via Web: Settings > Notifications > Uncheck “Pull Request push notifications” and customize “Automatically watch repositories”.
Via Web: Settings > Notifications > Add email address restrictions.
Step-by-step guide:
The GH CLI command above enables email restrictions via the API, meaning only emails associated with your primary GitHub email will be used for notifications. More comprehensively, log into GitHub web interface. Navigate to your Settings, then “Notifications.” Here, disable automatic watching of new repositories you create or are added to. Most critically, in the “Automatically watch repositories” section, select “Nothing” to ensure you only get notifications for repositories you manually choose to watch.
3. Scripting Automated Detection of Malicious PR Patterns
Create a simple script to monitor for PRs that tag an excessive number of external contributors, a key indicator mentioned in the threat intelligence.
`!/bin/bash`
` Fetch recent PRs for a repo and check mention count`
`PR_DATA=$(gh pr list –repo
`echo “$PR_DATA” | jq ‘.[] | select(.body | test(“@[a-zA-Z0-9-]+”; “g”)) | .number’`
` Integrate with GitHub Actions:`
`- name: Check PR for excessive mentions`
` run: |`
` MENTIONS=$(gh pr view ${{ github.event.pull_request.number }} –json body –jq ‘.body’ | grep -o ‘@[a-zA-Z0-9-]’ | wc -l)`
` if [ $MENTIONS -gt 5 ]; then exit 1; fi`
Step-by-step guide:
This Bash script uses `gh pr list` to get recent PRs and `jq` to parse the JSON, searching the PR body for any mention patterns (@username). The second part is a GitHub Actions workflow step that can be integrated into your repository’s CI/CD. It triggers on a pull request, counts the number of user mentions in the PR body, and fails the check if it exceeds a threshold (e.g., 5), alerting maintainers to review manually.
4. Investigating Deleted Repositories and Actors
Even after a malicious repository is deleted, you can often uncover historical data and link it to other activities using OSINT techniques and archived data.
`whois github-verification.com`
`curl -s “https://api.github.com/users/
`waybackurls github-verification.com | grep -i “github”`
Step-by-step guide:
When you identify a malicious domain like github-verification[.]com, use the `whois` command to query its registration date (this campaign used domains registered on 2025-09-23). Use `curl` to query the GitHub API for a suspicious user account; a very recent `created_at` date is a red flag. The `waybackurls` tool (from the `gobuster` package) checks the Wayback Machine for archived copies of the phishing site, which might reveal other targeted services or tactics.
5. Leveraging GitHub’s Audit Log for Enterprise Security
For organizations using GitHub Enterprise Cloud or Enterprise Server, the audit log is an indispensable tool for tracking user actions and identifying compromised accounts involved in such campaigns.
`gh api -X GET orgs//audit-log –paginate > audit_log.json`
`jq ‘.[] | select(.action == “repo.create” or .action == “repo.destroy”) | {actor, created_at, repo}’ audit_log.json`
`grep -i “gitcoin\|ycombinator” audit_log.json`
Step-by-step guide:
Organization owners can use the GH CLI to export the complete audit log. The `–paginate` flag ensures all pages are retrieved. The powerful `jq` command then filters this massive log for specific high-risk actions, such as the rapid creation and destruction of repositories, which is the lifecycle of these phishing campaigns. A simple `grep` can also search for keywords related to the impersonated brands within the log data.
- Implementing Pre-Receive Hooks to Block Malicious PR Content
For the highest level of security, organizations can implement server-side pre-receive hooks on their GitHub Enterprise instances to block PRs containing known phishing indicators before they are even created.
`!/bin/bash`
` Example Pre-Receive Hook Snippet`
`REFNAME=$1`
`while read oldrev newrev refname; do`
` if git diff –name-only $oldrev $newrev | grep -q “\.md$\|\.txt$”; then`
` if git diff $oldrev $newrev | grep -qi “github-verification\|claim\|fund”; then`
` echo “BLOCKED: PR contains blocked phishing keywords.”`
` exit 1`
` fi`
` fi`
`done`
Step-by-step guide:
A pre-receive hook runs on the GitHub server before a push is accepted. This script checks if the push contains changes to markdown or text files (common for PR descriptions). It then performs a `git diff` on the changes and searches for keywords associated with the campaign. If a match is found, the push is blocked entirely. This requires administrative access to the GitHub Enterprise server to configure.
- Community Vigilance and Reporting with the GH Community Discussions
As noted by security researchers, the official GitHub Community Discussions forum is a critical channel for real-time threat intelligence sharing.
`gh api -X GET “search/issues?q=repo:community/community discussion:174380″`
`gh api -X POST -H “Accept: application/vnd.github.v3+json” /repos/community/community/discussions/174380/comments -f body=”I encountered a similar PR impersonating Gitcoin on $(date).”`
Step-by-step guide:
Stay informed by periodically querying the key discussion thread (ID 174380) using the GH CLI. The first command searches for relevant posts. If you become a victim, contribute back to the community by using the second command to post a comment with your experience (without sharing sensitive details). This collective effort helps GitHub’s security team and the wider community understand the campaign’s scale and evolution.
What Undercode Say:
- The Perimeter is Now Your Inbox… and Your IDE. This attack demonstrates a fundamental shift. The trusted channels within a developer’s workflow—GitHub notifications, PR reviews—are the new attack vector. Traditional network and email security are irrelevant; the defense must exist within the development platform itself.
- Automation is Non-Negotiable for Scale. The transient nature of these PRs, deleted within hours, means manual reporting is often too slow. The only effective defense involves automated scripts integrated into CI/CD pipelines (like GitHub Actions) that scan for suspicious patterns (excessive mentions, specific keywords) in real-time and can automatically flag or block the activity.
The sophistication of this campaign lies in its exploitation of developer trust and workflow habits. Unlike broad phishing emails, these PRs are highly targeted, leveraging the credibility of the GitHub platform and the specific context of open-source contribution. The attackers’ operational security—deleting repositories quickly—shows a level of planning indicative of a persistent threat. This is not a one-off scam but likely a reconnaissance phase for a larger software supply chain attack, aiming to compromise developer credentials or inject malicious code into legitimate projects. The community-based response, centered around GitHub’s own discussion forum, is both a testament to the open-source spirit and a glaring indicator that platform-native defense tools are currently insufficient.
Prediction:
This GitHub PR phishing tactic is merely the precursor. We predict this will evolve into more automated, large-scale campaigns aiming directly at software supply chain compromise. The next phase will likely involve PRs that contain subtly malicious code changes, not just phishing links, targeting popular open-source dependencies. Attackers will use compromised maintainer accounts to submit plausible, but backdoored, updates, leveraging the same social engineering principles to get their PRs merged before security tools can catch them. The line between social engineering and code injection will blur, making DevSecOps and automated security scanning within the PR process absolutely critical.
🎯Let’s Practice For Free:
IT/Security Reporter URL:
Reported By: UgcPost 7376513071793643520 – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
