Don’t Let Your Out-of-Office Auto-Reply Help Scammers

We have all done it: you set your out-of-office auto-reply and head off on a well-deserved summer vacation. Your inbox hums along without you – but so do cyber criminals.

Out-of-office (OOO) messages, although helpful for letting colleagues and clients know you’re currently unavailable, can be a goldmine of information for scammers looking to launch phishing attacks. This potential risk is often overlooked, but it’s crucial to be aware of it.

Read: 8 Email Security Best Practices You Should Follow

What Are Out-of-Office Phishing Scams?

Instead of directly tricking you into clicking on malware, OOO phishing focuses on reconnaissance. OOO phishing scams occur when bad actors harvest information found in automatic email replies to plan future cyber attacks. These auto-replies often include:

• Full names and job titles
• Contact details (phone numbers or alternative emails)
• Time out of office dates
• Backup contacts or reporting structures
• Company branding and signatures

To a cyber criminal, this is more than out-of-office information – it’s intelligence. It tells them who is not monitoring their inbox, which colleagues to impersonate and how to tailor a believable phishing message. What makes these scams so effective is because they’re built on real-time, real-world context.

How Cyber Criminals Exploit OOO Messages

1. Email harvesting: Scammers send bulk emails to target organizations, hoping to trigger auto-replies.
2. Data collection: OOO replies reveal who’s away and for how long, their role with the company and internal contact names.
3. Spear phishing setup: Using the details above, attackers can then craft convincing emails to coworkers or external partners, posing as the absent employee or their backup contact.
4. Exploitation: These emails may request sensitive data, authorize wire transfers or ask for login credentials.

How to Protect Your Company

Turning off OOO replies isn’t always practical, especially in client-facing roles. So here are some additional steps you can take to reduce risk:

• Limit information in auto-replies: Avoid sharing specific travel details or exact return dates. Don’t list job titles or internal reporting structures. Never include personal contact information, including phone numbers and email addresses. Instead, list a general email address or phone number for alternative communication.
• Use external reply filters: If possible, set your system to send more limited or generic OOO messages to external contacts. Include detailed OOO information only in replies to internal emails.
• Consider a colleague: Another alternative to OOO emails is to have a colleague check your emails during your absence.
• Enable email security tools: Use advanced threat protection and email filtering to detect and blog suspicious activity. Monitor for signs of impersonation or domain spoofing. Enable multi-factor authentication (MFA) to prevent unauthorized access.
• Train your team: Regularly educate staff on phishing tactics, including those that leverage OOO replies. Reinforce protocols for handling financial requests, especially when someone is OOO.

Safeguard Your Information with Thriveon

OOO phishing scams, despite their seemingly low-tech nature, are surprisingly effective. A few harmless lines in an auto-reply can open the door to spear phishing, financial fraud or data breaches. With a few smart adjustments and ongoing training, you can ensure your OOO messages don’t become a cyber criminal’s way into your company.

Another alternative is to partner with an award-winning managed service provider (MSP) like Thriveon. We offer robust cybersecurity services that protect your company and its sensitive data from phishing attacks.

Schedule a meeting with us today to learn more.