What Is a Watering Hole Attack (and Why You Should Care)
Ever heard of a watering hole attack? It sounds like something from the wild, but it’s actually one of the sneakier tricks in the cyber world. Watering hole attacks are most commonly classified as a supply chain attack (or strategic web compromise).
Instead of chasing their victims, cybercriminals set a trap where they know their targets will go, just like predators waiting at a watering hole for unsuspecting animals to stop by for a drink.
In tech terms, that “watering hole” is a trusted website, one you visit all the time for business, industry news, or client services. Attackers quietly infect it with malicious code, and when you or your coworkers visit it, bam you’ve just been compromised.
How It Works
- Reconnaissance: The attacker figures out which websites your team visits regularly—like a vendor portal, industry association, or community forum.
- Compromise: They hack that website and inject malware or exploit code into it.
- Infection: When someone from your company visits, their browser runs the hidden script, downloading malware in the background.
- Exfiltration: Now the attacker has a foothold on your system or network, ready to steal data or credentials.
And the worst part? Because it’s coming from a legitimate, trusted website, traditional filters or security systems often don’t raise a red flag.
Why It’s So Dangerous
Watering hole attacks are hard to detect because everything looks normal—until it’s not.
- You’re hit through websites you trust.
- The malicious code is often hidden in legitimate content.
- Multiple users can be infected at once.
- The attacker can remain undetected for weeks or even months.
These attacks are increasingly popular among state-sponsored groups and targeted business espionage, especially when the goal is to infect an entire sector (like defense, finance, or law).
How to Protect Your Business
Here’s how to keep your team from “drinking from the wrong watering hole”:
- Keep software and browsers updated – Patch vulnerabilities fast; attackers love outdated plugins.
- Use advanced endpoint protection – Behavioral security catches weird activity that signature scanners miss.
- Segment your network – Limit how far an infection can spread.
- Monitor your vendors and partners – Make sure the sites you rely on aren’t compromised.
- Deploy DNS and email security solutions – Stop malicious redirects, attachments, and spoofed domains before they ever reach your team.
- Educate your staff – Even legit-looking sites can be hijacked; stay alert for unexpected downloads or pop-ups.
How ExchangeDefender Helps
At ExchangeDefender, we’re big believers in layered defense—because one tool can’t stop every type of threat.
- Our email security blocks phishing and malware before they hit your inbox.
- Our DNS protection helps stop users from reaching malicious or hijacked websites.
- And our policy controls give admins the ability to manage block and allow lists across entire organizations—no guesswork, no chaos.
It’s all about closing the gaps between trust and risk—so you can browse, click, and communicate safely.
👉 Learn more about securing your communications: www.ExchangeDefender.com
Reject vs Quarantine vs Allow: What Email Filtering Policies Really Do

If you’ve ever peeked under the hood of your email security, you’ve seen the terms Reject, Quarantine, and Allow. They sound simple, but these policies are the foundation of keeping your inbox safe, your business compliant, and your team productive.
With ExchangeDefender’s recent rollout of Advanced Reject Policies, it’s the perfect time to revisit what each of these settings actually does—and why getting them right matters more than ever.
Reject: The Bouncer at the Door
Think of Reject like a bouncer outside a nightclub. If the email doesn’t meet the rules, it never even gets through the door.
- Pros: Keeps dangerous or clearly unwanted mail out of your system entirely. No wasted storage, no wasted attention.
- Cons: If set too aggressively, you risk rejecting legit mail. That’s why ExchangeDefender gives you fine-grained control with Advanced Reject Policies—so you can block the bad stuff without hurting business.
Quarantine
Quarantine is the middle ground. Suspicious emails get flagged and held in a safe spot for review.
- Pros: Great for those “not sure” cases. Lets admins or users review questionable messages without risking exposure.
- Cons: Requires regular checks—if your team never looks at quarantine, important messages could be missed.
Allow: The VIP Pass
An Allow list tells your email security solution, “This sender is trusted—let them through, no questions asked.”
- Pros: Cuts down on false positives and ensures important partners or clients never get blocked.
- Cons: Dangerous if misused—once someone is on the allow list, they can bypass normal security checks. (Pro tip: prune your Allow list regularly!)
Why Balance Matters
Email filtering isn’t one-size-fits-all. The right mix of Reject, Quarantine, and Allow ensures your inbox is safe but not restrictive. ExchangeDefender now lets admins:
- Apply Reject Policies at domain and user levels.
- Fine-tune rules to comply with organizational or regulatory needs.
- Manage lists in bulk with Import/Export tools.
This means fewer missed emails, stronger security, and better compliance reporting.
Final Thoughts
Reject, Quarantine, and Allow aren’t just “settings”—they’re the rules that decide who gets in, who waits outside, and who never shows up. With ExchangeDefender’s new Advanced Reject Policies, you have more power than ever to tailor these rules to your business needs.
👉 Curious how to get started? Check out the full announcement here!


