Blog
May 6, 2026 06:00

Insights into the clustering and reuse of phone numbers in scam emails

Talos has recently started to collect and gather intelligence around phone numbers within emails as an additional indicator of compromise (IOC). In this blog, we discuss new insights into in-the-wild phone number reuse in scam emails.

April 15, 2026 06:00

The n8n n8mare: How threat actors are misusing AI workflow automation

Cisco Talos research has uncovered agentic AI workflow automation platform abuse in emails. Recently, we identified an increase in the number of emails that abuse n8n, one of these platforms, from as early as October 2025 through March 2026.

October 7, 2025 06:00

Too salty to handle: Exposing cases of CSS abuse for hidden text salting

A simple yet effective tactic, known as hidden text salting, is increasingly used by cybercriminals over the past few months to evade even the most advanced email security solutions, including those powered by machine learning and large language models.

July 2, 2025 06:00

PDFs: Portable documents, or perfect deliveries for phish?

A popular social engineering technique returns: callback phishing, or TOAD attacks, which leverage PDFs, VoIP anonymity and even QR code tricks.

March 13, 2025 06:00

Abusing with style: Leveraging cascading style sheets for evasion and tracking

Cascading Style Sheets (CSS) are ever present in modern day web browsing, however its far from their own use. This blog will detail the ways adversaries use CSS in email campaigns for evasion and tracking.

January 24, 2025 08:37

Seasoning email threats with hidden text salting

Hidden text salting is a simple yet effective technique for bypassing email parsers, confusing spam filters, and evading detection engines that rely on keywords. Cisco Talos has observed an increase in the number of email threats leveraging hidden text salting.

July 10, 2024 08:00

Hidden between the tags: Insights into spammers’ evasion techniques in HTML Smuggling

Talos is releasing a new list of CyberChef recipes that enable faster and easier reversal of encoded JavaScript code contained in the observed HTML attachments.

May 22, 2024 08:17

From trust to trickery: Brand impersonation over the email attack vector

Cisco recently developed and released a new feature to detect brand impersonation in emails when adversaries pretend to be a legitimate corporation.