- Pirates use an invisible unicode to encourage Android to open dangerous links from notifications
- The link seems normal, but Android secretly opens something else without warning or consent
- Even trust applications like WhatsApp and Instagram are vulnerable to this hidden notification feat
A security defect in the Android notification system could allow malicious actors to deceive users to open involuntary links or trigger hidden application actions, experts warned.
IO-No’s research affirm that the defect lies in the way Android analyzes certain unicode characters in notifications.
This creates a discrepancy between what users see and what the system deals with when the suggestion of “open link” appears.
What you see is not always what you get
The problem stems from the use of unicode invisible or special characters integrated into the URLs.
When included in a message, these characters can lead Android to interpret the visible text differently and the usable real link.
For example, a notification can obviously display “Amazon.com”, but the underlying code actually opens “zon.com”, with a zero-wide space character inserted.
The notification is displayed as “Ama[]Zon.com, “including the hidden character. However, the suggestion engine interprets that the hidden character as a separator, which leads to the launch of a completely different site.
In some cases, attackers can redirect users not only to websites, but also on deep links that interact directly with applications.
The report showed how apparently harmless shortened URL led to a WhatsApp call.
To make attacks less detectable, malicious actors can use URL shortcuters and integrate links to a text of appearance of confidence.
The defect becomes particularly dangerous when combined with application links or “deep links” which can silently trigger behaviors such as the launch of messages, calls or the opening of internal intention views without the intention of the user.
Tests on devices such as Google Pixel 9 Pro XL, Samsung Galaxy S25 and older Android versions have revealed that this bad behavior affects the main applications like Whatsapp, Telegram, Instagram, Discord and Slack.
Personalized applications have also been used to bypass characters filtering and validate the attack on several scenarios.
Given the nature of this defect, many standard defenses can fail. Even the best antivirus solutions can miss these exploits, as they often do not imply traditional malware downloads.
Instead, attackers handle the behavior of the user interface and use the application liaison configurations. Therefore, there is a need for termination points protection tools, which offer wider detection based on behavioral anomalies.
For users at risk of identification or application abuse, relying on identity theft protection services becomes essential to monitor unauthorized activity and secure the personal data exposed.
Until the implementation of a formal fix, Android users must remain cautious with notifications and links, in particular those of unknown sources or URL shortcutors.
