Watering Hole Attack
An attack method in which criminals compromise websites that the target audience regularly visits. Instead of attempting a direct attack on the target, the "watering hole" is poisoned—much like a predator waiting at a watering hole.
A watering hole attack is a targeted attack in which criminals compromise websites that their targets regularly visit. The name comes from a hunting strategy: instead of chasing prey, a predator waits at a watering hole. Attackers know that certain groups visit specific websites—and they infect those sites with exploits.
Why watering holes work
Direct attacks often fail: Spear-phishing is detected, VPNs are secured, and MFA prevents credential stuffing.
Watering holes bypass this: The target visits a website they trust—an industry association, trade magazine, supplier portal, or government website. This trust leads to lower security vigilance.
The Process of a Watering Hole Attack
- Reconnaissance: APT group identifies target (e.g., defense contractor) – OSINT: Which industry websites do employees visit? Candidates: Defense Industry Association, trade magazine, supplier
- Website Compromise: The attacker finds a vulnerability in the web server/CMS (often a WordPress plugin CVE), inserts malicious JavaScript code, and the code loads a browser exploit or executes a drive-by download
- Targeting: Code is often selective—only visitors from specific IP ranges (e.g., only if the IP belongs to a defense contractor); normal users see nothing unusual
- Exploitation: An employee of the target company visits the website; the browser exploit takes advantage of an unpatched vulnerability; malware is installed without user interaction
- Post-Exploitation: C2 connection established, lateral movement within the corporate network
Known Watering Hole Attacks
People’s Republic of China / APT41 (2019): At least 13 iOS zero-days embedded in websites visited by the Uyghur community. Visitors were automatically infected with iPhone malware.
Operation WildPressure (Kaspersky, 2020): Attack on the energy sector in the Middle East via compromised industry websites.
Polish Government (2017): Polish Financial Supervision Authority (KNF) website compromised—visitors from banks were infected with malware.
Detection Challenges
Watering holes are difficult to detect because:
- The infected website is legitimate and is visited regularly
- The exploit runs without user interaction (no click required)
- Selective targeting means: Few victims – hardly any reporting
- The exploit is often a zero-day exploit – no signature for antivirus
Protective Measures
Browser Security:
- Keep browsers up to date (automatic updates)
- Minimize browser extensions
- Disable JavaScript via NoScript/uBlock (on sensitive systems)
Network:
- Proxy with content inspection (TLS decryption, URL filtering)
- DNS filtering: Block known malware domains
- Web isolation: Browser runs in a cloud sandbox (Browser Isolation Technology)
Endpoint:
- EDR also detects zero-day exploits via behavioral analysis
- Application sandboxing (browser in sandbox mode)
- Regular patches – attackers often exploit known vulnerabilities
Threat Intelligence:
- Monitoring of compromised websites via TI feeds
- ISAC membership (industry-specific threat intelligence)
Watering holes demonstrate: Even disciplined users who do not open suspicious emails are at risk – if trusted resources are compromised.
