Email continues to be the weapon of choice for cybercriminals targeting businesses of all sizes. It’s easy, inexpensive, and alarmingly effective. Phishing messages, in particular, exploit the weakest link in any security strategy—humans. For every tool security experts develop to close that gap, cybercriminals find a way around it.
The latest technique making waves in the cybersecurity world is called hidden text salting—and it’s both simple and dangerous.
What Is Hidden Text Salting?
Hidden text salting is a new approach used by hackers to bypass email security filters. This technique involves embedding irrelevant language and concealed elements in the HTML or CSS code of emails. By “seasoning” emails with these hidden elements, cybercriminals can confuse spam filters, email parsers, and other tools designed to detect phishing attempts.
The result? Even advanced email filters can become baffled, allowing potentially harmful messages to slip through and reach your employees’ inboxes undetected.
How Hidden Text Salting Evades Detection
Cybersecurity researchers at Cisco Talos recently released a guide that highlights how hidden text salting works in practice:
- Irrelevant Language: In one attack, hackers embedded French words in the HTML code of phishing emails. Spam filters failed to recognize the irrelevant language as a threat, allowing the emails to bypass security measures.
- Cloaked Coding Techniques: Hackers also exploit features in HTML and CSS to conceal malicious traits. For example, they can include a “visibility:hidden” command to hide text that might otherwise trigger security filters.
- Obfuscated Links and Content: Cybercriminals can break up malicious URLs with hidden text or use encoded links that appear harmless at first glance.
These tactics create a significant challenge for traditional security systems that rely primarily on detecting specific keywords or known malicious signatures.
Why Hidden Text Salting Is a Major Threat
The danger of hidden text salting lies in its subtlety. Unlike obvious phishing attempts, these emails don’t immediately raise red flags. They often appear legitimate, increasing the chances of employees engaging with them.
Here’s why this threat is so effective:
- Stealth Attacks: Hidden text makes it difficult for both automated security tools and human eyes to detect threats.
- Trust Exploitation: If an email appears to come from a trusted source without triggering security alerts, employees are more likely to interact with it.
- Evolving Techniques: Cybercriminals continually refine these tactics to stay ahead of security protocols.
How to Protect Your Business from Hidden Text Salting
Combating hidden text salting requires a multi-layered approach to email security. Here are some effective strategies:
1. Read Emails in Plain Text Mode
Switching to plain text mode removes HTML and CSS elements that hackers exploit to hide malicious code. While it might make emails less visually appealing, it significantly reduces the risk of hidden threats.
2. Use Advanced Email Filtering Techniques
Upgrading your email filters to scan for unusual HTML and CSS properties can help detect hidden text salting attempts. Effective filters should:
- Analyze the structure and design of emails, not just the content.
- Identify patterns that suggest the presence of hidden elements.
3. Implement AI-Powered Security Solutions
AI-based email security tools use machine learning to detect subtle indicators of phishing. These solutions can:
- Analyze behavioral patterns and the context of emails.
- Identify hidden text and obfuscated links that traditional filters might miss.
- Adapt to emerging threats faster than manual systems.
The Role of Employee Training
While advanced technology can reduce the risk, human error remains a significant vulnerability. Ensure that your employees are trained to:
- Identify suspicious emails based on content and context.
- Report potential threats quickly to your IT security team.
- Avoid clicking on unexpected links or downloading attachments without verifying the sender.
Regular phishing simulations and security awareness programs can further strengthen your organization’s defenses.
What to Do If You Suspect Hidden Text Salting
If you suspect that hidden text salting has been used in an email:
- Isolate the email immediately to prevent accidental clicks.
- Report it to your IT team for analysis and threat mitigation.
- Update your email filters and security protocols based on new findings.
FAQ About Hidden Text Salting
1. How can I tell if an email contains hidden text salting?
Hidden text salting is designed to evade detection, making it difficult for untrained users to spot. However, unusual formatting, unexpected language, and unsolicited links can be red flags. Using plain text mode and advanced security tools is the most reliable way to detect these threats.
2. Is hidden text salting only a risk for large organizations?
No, businesses of all sizes are at risk. Cybercriminals target small and medium-sized enterprises precisely because they often lack the advanced security tools that larger organizations use.
3. Can traditional spam filters block hidden text salting?
Most traditional spam filters are not equipped to detect the advanced techniques used in hidden text salting. Upgrading to AI-powered security solutions and enhancing your filters to analyze email structure and code is essential.
Contact CTTS today for IT support and managed services in Austin, TX. Let us handle your IT so you can focus on growing your business. Visit CTTSonline.com or call us at (512) 388-5559 to get started!