Skip to main content
Press slash or control plus K to focus the search. Use the arrow keys to navigate results and press enter to open a threat.
Reconnecting to live updates…

WaSteal: 126 Chrome extensions, 148K installs, one Brazilian operator silently sending WhatsApp user data and ad cookies to its servers

0
Medium
Published: Wed May 13 2026 (05/13/2026, 21:29:06 UTC)
Source: Reddit NetSec

Description

A security incident named WaSteal involves 126 malicious Chrome extensions with approximately 148,000 installs. These extensions, operated by a single Brazilian actor, covertly exfiltrate WhatsApp user data and advertising cookies to external servers. The threat was reported on Reddit's NetSec community and is considered medium severity based on the available information. There is no indication of official patches or vendor advisories related to this issue. No known exploits in the wild have been confirmed. The incident highlights risks associated with malicious browser extensions silently collecting sensitive user data.

AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 05/19/2026, 19:17:29 UTC

Technical Analysis

WaSteal is a coordinated malicious campaign involving 126 Chrome extensions that have collectively been installed around 148,000 times. These extensions are controlled by one Brazilian operator who secretly sends WhatsApp user data and advertising cookies to their own servers. The information was disclosed via a Reddit NetSec post referencing an external report. There are no details about affected Chrome versions or specific technical exploitation methods. No vendor advisories or patches have been provided, and the extensions are not cloud services. The threat is primarily related to privacy violations through unauthorized data exfiltration by browser extensions.

Potential Impact

The impact involves unauthorized collection and transmission of WhatsApp user data and advertising cookies, potentially compromising user privacy and enabling targeted advertising or further profiling. Since the extensions are installed by users, the risk depends on user installation behavior. No direct evidence of exploitation beyond data theft is reported. There are no known exploits in the wild or confirmed vulnerabilities in Chrome itself.

Mitigation Recommendations

No official patches or vendor advisories are available for this threat. Users should immediately review and remove any suspicious or untrusted Chrome extensions, especially those related to WhatsApp or advertising. It is recommended to audit installed extensions regularly and only install extensions from trusted developers. Monitoring for unusual network activity related to browser extensions may help detect ongoing data exfiltration. Since this is a user-installed extension issue, remediation relies on user action and awareness.

Pro Console: star threats, build custom feeds, automate alerts via Slack, email & webhooks.Upgrade to Pro

Technical Details

Source Type
reddit
Subreddit
netsec
Reddit Score
0
Discussion Level
minimal
Content Source
reddit_link_post
Domain
null
Newsworthiness Assessment
{"score":32,"reasons":["external_link","established_author"],"isNewsworthy":true,"foundNewsworthy":[],"foundNonNewsworthy":[]}
Has External Source
true
Trusted Domain
false

Threat ID: 6a0cb742ba1db47362cb3df4

Added to database: 5/19/2026, 7:17:22 PM

Last enriched: 5/19/2026, 7:17:29 PM

Last updated: 5/20/2026, 10:30:19 AM

Views: 9

Community Reviews

0 reviews

Crowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.

Sort by
Loading community insights…

Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.

Need more coverage?

Upgrade to Pro Console for AI refresh and higher limits.

For incident response and remediation, OffSeq services can help resolve threats faster.

Latest Threats

Breach by OffSeqOFFSEQFRIENDS — 25% OFF

Check if your credentials are on the dark web

Instant breach scanning across billions of leaked records. Free tier available.

Scan now
OffSeq TrainingCredly Certified

Lead Pen Test Professional

Technical5-day eLearningPECB Accredited
View courses