Stopping a ClickFix WordPress compromise at a North Asian web services platform (June – August 2025)
At a glance
- Customer: IR‑1 subscriber — North Asian web services platform
- Environment: WordPress CMS, vendor‑managed web stack, endpoint telemetry (via an MDR/EDR provider)
- Attack type: WordPress admin account compromise; malicious JavaScript injection; ClickFix‑style visitor targeting
- Initial vector (assessed): Leaked / reused administrator credentials (credential compromise)
- Blackpanda services: IR‑1 rapid response, web compromise analysis, injected code review, dark‑web credential review, security recommendations
CHALLENGE
A web property became an attack delivery channel
The incident looked like a “website issue” at first — but the business risk was broader:
- A trusted web page can be weaponised to deliver malware or credential theft prompts to employees, customers, and partners.
- A single compromised admin login can quickly become site‑wide code execution (via injected scripts).
- Even if the company’s internal network isn’t breached, brand trust and customer safety are immediately at risk.
Blackpanda was engaged to investigate the compromise of the platform’s South Korea website based on available logs and evidence provided by the client and third parties.
Identity compromise in the CMS — not a plugin exploit
In this case, the intrusion path was identity‑driven:
- The compromise originated from unauthorised administrative access to the WordPress CMS using valid admin credentials.
- A dark‑web search identified multiple instances of the admin credentials appearing in leaked data, including exposures in 2025 — reinforcing credential compromise as the most likely intrusion vector.
Urgent questions leadership needed answered
- Is this a contained website compromise or a stepping stone into internal systems?
- Were customer or corporate datasets accessed or exfiltrated?
- Has the site been used to infect visitors — including employees?
SOLUTION
1. Rapid triage through IR‑1
Because the organisation was covered under Blackpanda IR‑1, Blackpanda incident responders could begin triage immediately — focused on confirming the intrusion mechanism, validating scope, and removing risk quickly.
2. Reconstructing the attacker’s actions in WordPress
Blackpanda reconstructed a clear attack chain:
- Unauthorised CMS login from an unusual geolocation.
- Installation of a legitimate plugin (Header Footer Code Manager) commonly abused to inject code into headers/footers site‑wide.
- Persistence and stealth mechanisms were used to reduce visibility of changes to plugin configuration.
- Injected scripts loaded JavaScript from a suspicious external domain — consistent with ClickFix‑style chains used for malvertising, credential harvesting, or drive‑by delivery.
3. Confirming whether this was a data‑theft incident
Blackpanda assessed internal and external telemetry for signs of data exfiltration and found no evidence of exfiltration, consistent with ClickFix tactics (weaponising the site to target visitors rather than extract data from the site).
4. Hardening plan that closes the real gap: credential and access hygiene
Blackpanda’s recommendations prioritised practical controls that prevent repeat compromise:
- Enforce MFA for CMS and privileged access
- Add integrity monitoring on key CMS directories/files
- Deploy or tune WAF rules to block script injection and cloaked spam
- Strengthen vendor access controls and monitoring
- Improve endpoint telemetry segregation and investigator‑level visibility where MSP tooling is used
RESULTS
1. Confirmed scope and attack intent
Blackpanda confirmed the intrusion pattern aligned with ClickFix: compromise via stolen admin credentials, followed by plugin‑enabled script injection to target site visitors — not a data‑exfiltration operation.
2. Validated: no evidence of data theft
No evidence of data exfiltration was identified in the reviewed telemetry and analysis.
3. Stronger web security baseline after remediation
The remediation approach emphasised proactive hygiene (MFA, attack‑surface reduction, integrity monitoring, WAF, and vendor governance) so that future incidents are harder to execute and faster to detect.
4. Cost‑efficiency snapshot (IR‑1)
For many organisations, the hardest part of a web incident is not “clean‑up” — it’s getting experienced responders engaged fast, without emergency procurement.
- Assumption: 500 endpoints covered under IR‑1; ~70 hours of incident response effort
- IR‑1 annual cost (indicative): 500 × USD 15 = USD 7,500
- Ad‑hoc response cost (indicative): 70 × USD 500 = USD 35,000
Under this simplified comparison, IR‑1 can represent an illustrative saving of ~USD 27,500 (~79%) versus a comparable one‑off engagement.
All prices are indicative and subject to change at any time.
FAQ: WordPress Compromises, ClickFix, and IR‑1
Q1. What is the ClickFix campaign?
ClickFix is a widespread web compromise pattern where attackers use stolen WordPress admin credentials to install “legitimate” plugins and inject malicious scripts site‑wide to trick visitors into running attacker‑controlled actions.
Q2. Was this caused by a vulnerable WordPress plugin?
In this case, evidence points to credential compromise first — then a legitimate plugin was installed and abused for code injection.
Q3. Was there evidence of data exfiltration?
No evidence of exfiltration was identified, and the observed behavior aligns with visitor‑targeting rather than data theft.
Q4. How do we reduce the risk of a repeat incident?
Enforce MFA, reduce attack surface, implement integrity monitoring and WAF protections, and tighten vendor access controls and visibility.
Q5. When should we escalate to incident response?
If you see unexplained admin logins, newly installed plugins, injected scripts, SEO poisoning, or suspicious redirects — escalate immediately to contain impact and confirm scope.
What this means for you
If you operate high‑trust web properties, a single compromised CMS admin account can quietly turn your site into an attack platform. Blackpanda IR‑1 is designed for these moments — fast access to incident responders, clear scope answers, and concrete controls that prevent repeat compromise.
