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Phishing 2 min read

You’ll Never Guess Which Day of the Week is #1 for Phishing

Brad Slavin
Brad Slavin General Manager
Updated May 23, 2025

Quick Answer

Monday is the most active day for phishing email, with research finding more than 30% of opportunistic phishing and scam mail sent on the first weekday and the volume tapering through the week. The reason attackers prefer Mondays is 'social jet lag': sleep patterns shift over the weekend, recipients open Monday inboxes overwhelmed and under-caffeinated, and that is when judgment is weakest. Awareness alone is not enough because attackers only need one click out of many to succeed. The control that maps to this pattern is real-time phishing protection that filters mail and re-checks every link at click time, so the Monday-morning lapse does not turn into a credential or malware compromise.

Phishing

Say what you will about hackers, but they do their homework. They don’t just send out phishing emails willy nilly. The send them out and measure their effectiveness, including what day of the week is the most effective to send them on.

According to an article on NationalCybersecurity.com, research “has revealed more malicious emails are delivered on Monday mornings than any other day.” As if Mondays weren’t bad enough already. “More than 30 per cent of all cyber-attack emails sent by opportunistic hackers and scammers go out on the first day of the week, declining steadily with each passing weekday.”

hackers

Apparently, the explanation for the Monday attacks is something called “social jet lag (caused by changing your sleeping patterns over the weekend.” The theory goes that since you’ve just spent the last two days sleeping in, on Monday morning, your body hasn’t adjusted, so early on you’re not quite awake yet. And that’s when the hackers come calling. They probably time it to arrive before you’ve had your coffee too.

According to the article, “What attackers are looking for is the maximum point of vulnerability, and if you think about when we are most vulnerable, it’s when we’re occasionally overwhelmed.” Like on Monday mornings with 100 emails in our inbox? Clever!

I think we can all agree that hackers are smart, relentless and continuously evolving. If there’s a weakness, they will find it. Really, what chance have you got? You can be alert 99% of the time. The hackers only need to get it by you once. You’d be wise to get some help.

phishing

If you’d like to protect yourself from these persistent hackers on Monday and every other day, you need phishing protection software with real-time link protection from DuoCircle. It blocks malicious attachments and malicious links. It sets up in 10 minutes, costs pennies per email per month and comes with 24/7 live technical support.

Don’t let hackers take advantage of your sleep patterns. Take away their Monday morning advantage with phish protection from DuoCircle.com.

Brad Slavin
Brad Slavin

General Manager

General Manager at DuoCircle. Product strategy and commercial lead across the email security portfolio.

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