Remember the Simjacker vulnerability?
Earlier this month, we report a major unparalleled weakness in a wide range of SIM-cards which a non-namened monitoring company actively used in the wild, by only sending specific SMS to their telephone numbers to remotely compromise targeted mobile phones.
If you remember, the vulnerability of Simjacker lies in a dynamic SIM toolkit called S@T Browser which is provided to mobile operators in at least 30 countries with a range of SIM cards including eSIM.
The S@T browser is now no longer the only dynamic SIM tool-kit containing the Simjacker problem that can be remotely exploited from any part of the globe without any authorisation — whichever device the victims or mobile operating systems use.
WIB SIM ToolKit Also Leads To SimJacker Attacks
After Simjacker’s revelation the Ginno Security Lab researcher Lakatos reached the Hacker News earlier this week and found that it is also possible to use another dynamic SIM kit, called Wireless Internet Browser (WIB), which exposes hundreds of millions of remote phone users.
Lakatos said The Hacker News that this vulnerability had discovered back in 2015 but decided not to make it public, as “bad guys can abuse telefones that run vulnerable SIMs remotely” the process of patching such a defect is very complex.
In addition, Lakatos claimed he also discovered S@T browser independently and provided videos of the vulnerability of Simjacker with further information that AdaptiveMobile Security Researchers did not publish yet.
WIB Toolkit was created and maintained by SmartTrust, a leading provider worldwide of SIM toolkit solutions for over 200 mobile operators, including AT & T, Claro, Etisalat, KPN, TMobile, Telenor and Vodafone, according to certain press releases.
WIB and S@T Browsers Flaw Could Lets Attackers Target Mass Users
Like the S@T Browser, WIB toolkit also allows mobile operators to provide their clients with a variety of essential services, subscriptions and value-added services or change their core network settings.
The dynamic SIMs toolkit allows Mobile operators to generate new functionality and fly options based on information supplied by a central server instead of a pre-fixed menu that is installed.
“OTA is based on client/server architecture where at one end there is an operator back-end system (customer care, billing system, application server…) and at the other end there is a SIM card,” the researcher explained in a blog post.
The flaw in both S@T and WIB Browsers can be exploited to perform several tasks on a targeted device just by sending an SMS containing a specific type of spyware-like code.
- Retrieving targeted device’ location and IMEI information,
- Sending fake messages on behalf of victims,
- Distributing malware by launching victim’s phone browser and forcing it to open a malicious web page,
- Performing premium-rate scams by dialing premium-rate numbers,
- Spying on victims’ surroundings by instructing the device to call the attacker’s phone number,
- Performing denial of service attacks by disabling the SIM card, and
- Retrieving other information like language, radio type, battery level, etc.
How Does SimJacker Attack Work Against WIB or S@T Enabled SIMs?
As practically demonstrated in the video and illustrated in the above
diagram that Lakatos shared with The Hacker News, both Simjacker and
WIBattack attacks can be summarized in four following steps:
- Step 1 — Attackers send a malicious OTA SMS to the victim’s phone number containing an S@T or WIB command such as SETUP CALL, SEND SMS, or PROVIDE LOCATION INFO.
- Step 2 — Once received, the victim’s mobile operating system forwards this command to the S@T or WIB browser installed on the SIM card, without raising an alert or indicating the user about the incoming message.
- Step 3 — The targeted browser then instructs the victim’s mobile operating system to follow the command.
- Step 4 — The victim’s mobile OS then performs the corresponding actions.
Lakatos says he also reported his findings to the GSM Association
(GSMA), a trade body that represents the interests of mobile operators
The telecom industry needs urgent countermeasures to prevent Simjacker, WIBattack, and other evolving threats to protect billions of mobile phone users worldwide.
How to Detect Simjacker Attacks?
Meanwhile, the researcher also told The Hacker News that he is working
on a mobile phone app, to be released soon, that would allow users to
scan their SIM cards to detect if it’s vulnerable to Simjacker
vulnerability or not.
Developed by researchers at SRLabs, there’s another Android app, called SnoopSnitch, which can detect attacks based on suspicious binary SMS including Simjacker and alert users of it.
You can download SnoopSnitch from Google Play Store, but you need to have a rooted Android smartphone with a Qualcomm chipset for the SMS attack alerting feature to work.
We also reached out to AdaptiveMobile Security firm for a comment but have not heard back from them yet.