Beware the 'rn' Trick: How Hackers Fool You into Thinking You're on a Legit Site
In a clever and deceptive move, hackers have found a way to exploit a simple typo to impersonate trusted brands like Microsoft and Marriott. This sophisticated phishing tactic is all about visual trickery, and it's a reminder that even the smallest details can have big security implications.
The 'rn' Homoglyph Attack Explained
Attackers are registering domains that play a clever trick on your eyes and brain. By replacing the letter 'm' with the characters 'rn' (r + n), they create URLs that, at a quick glance, look almost identical to the real thing. For example, 'rnarriottinternational.com' might appear as 'marriottinternational.com' to your eyes, but it's not.
This exploit takes advantage of how modern fonts render text. In many typefaces, the letters 'r' and 'n' together look very similar to an 'm', and hackers are using this to their advantage. When you quickly scan a URL, your brain might 'autocorrect' and read 'm' instead of 'rn', and that's the cognitive shortcut these attackers are counting on.
Marriott and Microsoft: Targets of This Visual Deception
Security researchers have identified a cluster of malicious domains targeting Marriott International and its guests. These phishing sites are designed to steal loyalty account credentials and personal guest information. The attackers have gone to great lengths to replicate Marriott's branding and website structure, increasing the chances of successful credential theft.
Additionally, a parallel campaign has been discovered targeting Microsoft users. The domain 'rnicrosoft.com' is used to impersonate Microsoft communications, complete with official logos and language patterns. This attack is particularly dangerous on mobile devices, where the reduced screen size makes distinguishing 'rn' from 'm' almost impossible.
How to Protect Yourself from This Visual Hack
Here are some tips to avoid falling victim to this clever phishing tactic:
- Verify Sender Information: On mobile email apps, tap the sender's name to expand the full email address. Carefully check for the 'rn' substitution before interacting with any content.
- Hover to Inspect: Desktop users can hover their cursor over hyperlinks to preview the actual destination URL in the status bar, without clicking.
- Manual Navigation: When receiving urgent emails, avoid clicking embedded links. Instead, open a new browser window and manually type the legitimate domain (e.g., marriott.com, microsoft.com).
- Use Password Managers: These tools can provide protection by refusing to auto-fill credentials on unrecognized domains, preventing accidental credential disclosure.
Indicators of Compromise (IOCs): A Quick Reference Guide
| Phishing Domain | Impersonated Service | Typosquatting Technique | Detection Difficulty |
| --- | --- | --- | --- |
| rnarriottinternational.com | Marriott International | 'm' replaced with 'rn' | Critical |
| rnarriotthotels.com | Marriott Hotels | 'm' replaced with 'rn' | Critical |
| rnicrosoft.com | Microsoft 365 / Login | 'm' replaced with 'rn' | High (Mobile) |
| micros0ft.com | Microsoft | 'o' replaced with '0' | Medium |
| microsoft-support.com | Microsoft Support | Hyphenation / Suffix | Low |
Stay Informed, Stay Safe
This threat highlights the importance of staying vigilant and educated about potential security risks. Incorporate these tips into your digital security practices and share this knowledge with others to help create a safer online environment. Remember, a little awareness can go a long way in protecting yourself and your data.
Stay tuned for more cybersecurity updates and insights! Feel free to share your thoughts and experiences in the comments below.
