Cybersecurity researchers have found two malicious Google Chrome extensions with the identical identify and revealed by the identical developer that include capabilities to intercept visitors and seize consumer credentials.
The extensions are marketed as a “multi-location community velocity check plug-in” for builders and international commerce personnel. Each the browser add-ons can be found for obtain as of writing. The small print of the extensions are as follows –
- Phantom Shuttle (ID: fbfldogmkadejddihifklefknmikncaj) – 2,000 customers (Revealed on November 26, 2017)
- Phantom Shuttle (ID: ocpcmfmiidofonkbodpdhgddhlcmcofd) – 180 customers (Revealed on April 27, 2023)
“Customers pay subscriptions starting from ¥9.9 to ¥95.9 CNY ($1.40 to $13.50 USD), believing they’re buying a professional VPN service, however each variants carry out equivalent malicious operations,” Socket safety researcher Kush Pandya stated.
“Behind the subscription facade, the extensions execute full visitors interception by way of authentication credential injection, function as man-in-the-middle proxies, and constantly exfiltrate consumer information to the risk actor’s C2 [command-and-control] server.”
As soon as unsuspecting customers make the cost, they obtain VIP standing and the extensions auto-enable “smarty” proxy mode, which routes visitors from over 170 focused domains by way of the C2 infrastructure.
The extensions work as marketed to strengthen the phantasm of a purposeful product. They carry out precise latency exams on proxy servers and show connection standing, whereas conserving customers at the hours of darkness about their foremost purpose, which is to intercept community visitors and steal credentials.
This entails malicious modifications prepended to 2 JavaScript libraries, specifically, jquery-1.12.2.min.js and scripts.js, that come bundled with the extensions. The code is designed to mechanically inject hard-coded proxy credentials (topfany / 963852wei) into each HTTP authentication problem throughout all web sites by registering a listener on chrome.webRequest.onAuthRequired.
“When any web site or service requests HTTP authentication (Fundamental Auth, Digest Auth, or proxy authentication), this listener fires earlier than the browser shows a credential immediate,” Pandya defined. “It instantly responds with the hardcoded proxy credentials, fully clear to the consumer. The asyncBlocking mode ensures synchronous credential injection, stopping any consumer interplay.”
As soon as customers authenticate to a proxy server, the extension configures Chrome’s proxy settings utilizing a Proxy Auto-Configuration (PAC) script to implement three modes –
- shut, which disables the proxy function
- all the time, which routes all internet visitors by way of the proxy
- smarty, which routes a hard-coded listing of greater than 170 high-value domains by way of the proxy
The listing of domains consists of developer platforms (GitHub, Stack Overflow, Docker), cloud providers (Amazon Internet Companies, Digital Ocean, Microsoft Azure), enterprise options (Cisco, IBM, VMware), social media (Fb, Instagram, Twitter), and grownup content material websites. The inclusion of pornographic websites is probably going an try and blackmail victims, Socket theorized.
The web results of this habits is that consumer internet visitors is routed by way of risk actor-controlled proxies whereas the extension maintains a 60-second heartbeat to its C2 server at phantomshuttle[.]house, a website that is still operational. It additionally grants the attacker a “man-in-the-middle” (MitM) place to seize visitors, manipulate responses, and inject arbitrary payloads.
Extra importantly, the heartbeat message transmits a VIP consumer’s e mail, password in plaintext, and model quantity to an exterior server through an HTTP GET request each 5 minutes for steady credential exfiltration and session monitoring.
“The mix of heartbeat exfiltration (credentials and metadata) plus proxy MitM (real-time visitors seize) gives complete information theft capabilities working constantly whereas the extension stays lively,” Socket stated.
Put in another way, the extension captures passwords, bank card numbers, authentication cookies, shopping historical past, type information, API keys, and entry tokens from customers accessing the focused domains whereas VIP mode is lively. What’s extra, the theft of developer secrets and techniques might pave the best way for provide chain assaults.
It is at the moment not identified who’s behind the eight-year-old operation, however the usage of Chinese language language within the extension description, the presence of Alipay/WeChat Pay integration to make funds, and the usage of Alibaba Cloud to host the C2 area factors to a China-based operation.
“The subscription mannequin creates sufferer retention whereas producing income, and the skilled infrastructure with cost integration presents a facade of legitimacy,” Socket stated. “Customers consider they’re buying a VPN service whereas unknowingly enabling full visitors compromise.”
The findings spotlight how browser-based extensions have gotten an unmanaged danger layer for enterprises. Customers who’ve put in the extensions are suggested to take away them as quickly as potential. For safety groups, it is important to deploy extension allowlisting, monitor for extensions with subscription cost methods mixed with proxy permissions, and implement community monitoring for suspicious proxy authentication makes an attempt.
