Threat Intelligence Blog
Research, insights, and updates from the isMalicious team.
SPF Permerror: Fix the DNS Lookup Limit
Trace SPF dependencies, distinguish permerror from fail, and reduce DNS lookups while testing every sending service.
SMTP 550 5.7.1: Find the Cause of an Email Rejection
A 550 5.7.1 rejection can involve recipient policy, authentication, or reputation. Use the full diagnostic and delivery traces to find the cause.
Is Your Email Leaking Data? How to Check Email Reputation
Learn why email reputation matters for security and deliverability, and how to check if an email address is compromised or malicious.
Why Your SaaS Needs to Block Disposable Email Addresses Immediately
Disposable and temporary email addresses can enable fraud, spam, and abuse. Learn how disposable-domain detection supports account controls and sender reputation.
Email Authentication: Implementing DMARC, SPF, and DKIM for Email Security
Email spoofing enables phishing and business email compromise attacks. Learn how DMARC, SPF, and DKIM authentication protocols protect your domain from being impersonated in cyberattacks.
Business Email Compromise: The Multi-Billion Dollar Threat
BEC attacks cost organizations billions annually through sophisticated impersonation and social engineering. Learn how domain spoofing detection and threat intelligence can protect your organization from CEO fraud and invoice scams.
Expert Threat Intelligence Analysis
Our blog features in-depth analysis from our threat research team. Each article is backed by real data from our analysis of millions of malicious domains, IPs, and URLs across the global threat landscape. Topics include ransomware campaigns, phishing techniques, malware distribution networks, and emerging threat trends. We publish specific intelligence that security teams can immediately use to improve their defenses.
Practical Security Guidance
Beyond threat analysis, we share practical guidance for security practitioners. Our tutorials cover API integration, SIEM configuration, threat hunting techniques, and building effective threat intelligence programs. Whether you're a SOC analyst, security engineer, or CISO, you'll find content tailored to your role and experience level.
Stay Ahead of Emerging Threats
The threat landscape evolves constantly. Our blog keeps you informed about the latest attack techniques, newly discovered vulnerabilities, and emerging threat actors. Subscribe to our newsletter for weekly digests of the most important developments in cybersecurity.
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