It was a busy week for cybersecurity threats. Hackers exploited a flaw in VMware software, giving them full control over virtual machines. At the same time, Microsoft flagged a phishing campaign that used AI written code in fake file sharing emails to trick victims. A new Android Trojan, Datzbro, also spread through fake senior community apps, letting criminals take over phones. To top it off, the Confucius group launched fresh phishing attacks, and researchers found a malicious Python package that secretly installed backdoors on Windows systems.
The Simple Mail Transfer Protocol (SMTP) stands as the cornerstone of email delivery across the internet. As an email protocol, SMTP is responsible for the sending and relaying of messages between email servers in the TCP/IP suite. Designed originally in the 1980s, SMTP governs the outgoing mail server infrastructure and serves as the standard method used by mail transfer agents (MTAs) such as Postfix, Sendmail, Exim, and Microsoft Exchange Server to forward email from a mail user agent (MUA) or an email client to the destination email server.
Invoice fraud doesn’t start with a Hollywood-grade hack. It starts with a believable message, a familiar vendor name, and a PDF that looks routine. Attackers know accounts payable runs on documents, so they hide social engineering and malware inside “invoice” attachments to reroute payments or plant a foothold. This guide lays out a practical, technical path to process PDF invoices safely—without turning your finance team into part-time security analysts.
DomainKeys Identified Mail (DKIM) is a critical component of modern email authentication frameworks designed to enhance email security by verifying sender identities and ensuring message integrity. Introduced as an open standard and formalized by RFC 6376, DKIM employs public key cryptography to cryptographically sign email headers and message body, allowing mailbox providers like Google’s Gmail, Microsoft 365, and Yahoo to verify that emails originate from legitimate senders.
Troubleshooting SPF syntax errors: Tips for fixing the most common mistakes
by DuoCircle
When you configure SPF for your domain, there are a lot of things that can go wrong and wreck your entire setup. And if your SPF configuration is not done right, your emails will be at risk, the risk of being rejected, marked as spam, or worse, being impersonated by threat actors.
An online SMTP server functions as a critical component of the email protocol infrastructure, facilitating the transfer of outgoing emails over the internet. SMTP, or Simple Mail Transfer Protocol, is the standardized protocol that governs how email servers, or mail transfer agents (MTAs), communicate to ensure reliable email delivery. Acting as an outgoing mail server, an SMTP server handles the sending process, routing emails through SMTP relay channels to the recipient’s email server.
This week saw a wave of cyber incidents across critical sectors. A stealthy campaign used the BRICKSTORM backdoor to hide inside networks for over a year, while a flaw in Pandoc was exploited in attempts to steal AWS credentials. Libraesva patched a bug in its Email Security Gateway that attackers are already abusing. Airports across Europe faced massive disruptions after a ransomware attack, and researchers flagged ShadowV2, a new Docker-targeting botnet offering DDoS-for-hire services.
Email hosting servers constitute the backbone of modern business communication infrastructure. At their core, these servers manage the sending, receiving, and storage of electronic mail by leveraging robust email server software. Their configuration involves the integration of various email protocols such as SMTP (Simple Mail Transfer Protocol), IMAP (Internet Message Access Protocol), and POP3 (Post Office Protocol 3), ensuring smooth mail routing between mail transfer agents (MTAs) and mail delivery agents (MDAs). Businesses depend on these servers to provide reliable communication channels facilitated through inbound mail servers, outbound mail servers, and mailboxes with efficient mailbox storage management.
When DKIM is not properly aligned for your domain, your outgoing emails may be at risk of tampering. That means anyone can make unauthorized changes to your email while it’s on the way to the receiver’s inbox, and the recipient might never even know it was altered.
Sender Policy Framework (SPF) is a critical email authentication protocol that plays a vital role in bolstering email security. Essentially, SPF allows domain owners to specify which mail servers are authorized to send emails on their behalf by publishing specific rules within DNS TXT records. This configuration helps receiving mail servers verify if incoming messages claiming to be from a particular domain are indeed sent from legitimate sources.
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