For school children, summer means lazy days of swimming pools, splash pads, melting ice cream cones, and camp. For cybersecurity professionals, it means being on guard 24/7, because cybercriminals don’t take a summer break.
The summertime impact
Cyberattacks now occur every 39 seconds globally, while worldwide cybercrime costs are estimated to hit $10.5 trillion annually by 2025. Additionally, summer brings its own set of complications that amplify these already staggering statistics. While you are applying the next layer of sunscreen by the hotel pool, hackers are hard at work.
Reduced staffing during summer vacation season creates critical vulnerabilities, with temporary staff often lacking adequate security awareness training and being more susceptible to phishing attacks. Meanwhile, the increase in remote work from vacation rentals and coffee shops exposes organizations to unsecured WiFi risks, creating new attack vectors that cybercriminals are eager to exploit.
“While summer usually means vacation for most people, we’ve seen quite the opposite on the cybersecurity front—phishing scams are spiking, artificial intelligence (AI)-generated fraud is getting smarter, and remote access vulnerabilities are still a major weak spot,” says John Hansman, CEO of cybersecurity company Truit.
Perhaps most troubling is the timing factor.
Automated out-of-office replies provide attackers with valuable intelligence about employee absences, allowing them to time their attacks for maximum impact when security teams are operating with skeleton crews.
The convergence of relaxed vigilance, reduced staffing, and increased online activity creates a Petri dish of summer cybercrime.
What MSPs need to do
For managed service providers (MSPs) serving clients across multiple industries, understanding these seasonal threat patterns isn’t just helpful—it’s the key to maintaining robust security postures when businesses are most vulnerable.
Mike Kutlu, GTM Operations at c/side, mentions that while many organizations are focused on endpoint and network-layer risks, there’s a growing storm at the browser layer that’s catching even seasoned MSPs/managed security services providers (MSSPs)/chief information security officer (CISAs) off guard.
“This summer, browser-side attacks, especially those exploiting third-party JavaScript dependencies, are emerging as one of the most active and least visible threat vectors,” Kutlu adds, mentioning that these attacks don’t target your infrastructure directly, but instead weaponize code that loads in the end user’s browser, often from trusted tools like analytics, chat widgets, or payment processors.
“The kicker is that most organizations have no idea what’s running in that browser environment or how it’s changing,” as Kutlu notes that summer is prime time for campaigns like these.
To stay ahead, Kutlu advises that MSPs and MSSPs should prioritize a few key actions, including:
- Regularly auditing client websites to inventory all first and third-party scripts and understand what those scripts actually do.
- Adding real-time monitoring in place to catch unauthorized changes to scripts and HTTP headers (sampling-based approaches are no longer sufficient).
- Ensuring clients comply with PCI DSS 4.0.1, which now mandates tamper-detection mechanisms for any site handling cardholder data.
- Scrutinizing the provenance of every script, as even a widely used library can become malicious after a silent update or DNS takeover.
The seasonal spike in cyberthreats
Meanwhile, Brian Blakey, vice-president of cybersecurity strategies at ConnectSecure, agrees that summer is an important time for MSPs to stay vigilant. “For cybersecurity professionals, summer is anything but quiet,” he shares, noting that major U.S. holidays like Memorial Day, July 4th, and Labor Day consistently bring sharp spikes in cyberattacks. Ransomware incidents can rise by as much as 30 percent during these low-staff periods.
“Threat actors know that IT and security teams are stretched thin, with slower response times and relaxed oversight creating the perfect storm for exploitation,” Blakey asserts, adding that what’s especially “hot” this summer isn’t just AI-powered malware or new zero-days – it’s human downtime.
“Lax coverage, temporary admin access, and out-of-office replies all become attack vectors. We’re seeing a rise in weaponized OOO replies, spoofed multi-factor authentication (MFA) fatigue prompts, and ransomware campaigns precisely timed for maximum impact before a long weekend,” as he adds that summer is the peak season for cybersecurity – not a lull. “MSPs and CISAs must stay proactive by tightening access controls, strengthening coverage during holidays, and treating long weekends as high-risk periods. Because while your team may be out of office, adversaries are very much clocked in.”
Summer may signal downtime for many businesses, but for cybercriminals, it’s go time. With rising attack volume, smarter tactics, and human vulnerabilities at their peak, MSPs and MSSPs must treat the season as a critical threat window, not a break. Staying vigilant, tightening controls, and monitoring overlooked areas like browser activity aren’t just best practices. They’re essential moves to keep clients safe while everyone else is unplugging.
Photo: Dragon Images / Shutterstock
This post originally appeared on Smarter MSP.