Simjacker Exploits S@T Browser to Affect a Billion Users



Platform agnostic attack, Simjacker allows hackers to remotely exploit the victims' phone by sending a SMS which contains a malicious code; the code gives instructions to the universal integrated circuit card (UICC)/ SIM card placed inside the targeted device to retrieve and carry out sensitive commands.

The attack is set into motion as soon as the 'attack SMS' sent via another remote handset, is received by the targeted device. The process involves a series of SIM Toolkit (STK) directions particularly configured to be sent on to the SIM Card inside the victim's device.

To ensure a proper execution of these instructions, Simjacker exploits the S@T Browser, which is a software found in SIM cards. After receiving the 'attack SMS', SIM card resorts to the S@T Browser library for setting up the execution friendly environment which can trigger logic on the infected device.

S@T Browser, a legacy browser technology placed inside the SIM cards on a number of handsets, was typically used to send promotional messages or spam text messages. However, the attackers went on exploiting it for obtaining device's location and its unique International Mobile Equipment Identity (IMEI).

The attacker sends a SMS to the S@T browser asking it for the aforementioned information which it would obtain and store on to the SIM card. Then, the attacker would send another SMS to acquire the stored information. These messages are send and received in binary codes, unlike regular messages. It doesn't alert the victim in any manner and hence qualifies to be a highly effective tool for attacking mobile phones via messages.

Referencing from the findings of mobile carrier security company AdaptiveMobile Security, 

"The main Simjacker attack involves an SMS containing a specific type of spyware-like code being sent to a mobile phone, which then instructs the SIM Card within the phone to ‘take over’ the mobile phone to retrieve and perform sensitive commands." 

"We believe this vulnerability has been exploited for at least the last two years by a highly sophisticated attacker group." The report reads. 

Notably, the exploit is working as a lot of operators are failing to check the origin of these binary codes (SMS), which can be blocked by configuring the firewall technology in their corresponding networks, advises AdaptiveMobile.






Hackers Exploiting a Critical Weakness In Mobile Phones to Track Location



The interface designed for the usage of cell carriers is being exploited heavily by attackers. It allows the cell carriers to get in direct touch with the SIM cards inside subscribers' smartphones, the interface can be employed by the carriers for allowing subscribers to make use of the data stored on their SIM card to provide account balances along with other specialized services.

Hackers can secretly track the location of subscribers by exploiting the interface and giving commands to acquire the IMEI identification code of device; the Simjacker exploit further allows them to carry out actions such as making calls or sending messages.

According to the researchers at AdaptiveMobile Security, the working of the Simjacker exploit is not limited to a few devices, rather, it can be carried out on a wide range of mobile phones, irrespective of their software or hardware.

Unfolding the various aspects of the attack, Dan Guido, a mobile security expert and the CEO of security firm Trail of Bits told Ars, “This attack is platform-agnostic, affects nearly every phone, and there is little anyone except your cell carrier can do about it.”

While commenting on the issue, Karsten Nohl, the chief scientist at SRLabs, told Ars, “We could trigger the attack only on SIM cards with weak or non-existent signature algorithms, which happened to be many SIM cards at the time,”

 “AdaptiveMobile seems to have found a way in which the same attack works even if signatures are properly checked, which is a big step forward in attack research.” He added.


Sim swapping attacks hit US cryptocurrency users

Something strange happened last week, with tens of US-based cryptocurrency users seeing SIM swapping attacks.

Numerous members of the cryptocurrency community have been hit by SIM swapping attacks over the past week, in what appears to be a coordinated wave of attacks.

SIM swapping, also known as SIM jacking, is a type of ATO (account take over) attack during which a malicious threat actor uses various techniques (usually social engineering) to transfers a victim's phone number to their own SIM card.

The purpose of this attack is so that hackers can reset passwords or receive 2FA verification codes and access protected accounts.

These types of attacks have been going on for half a decade now, but they've exploded in 2017 and 2018 when attackers started focusing on attacking members of the cryptocurrency community, so they could gain access to online accounts used for managing large sums of Bitcoin, Ethereum, and other cryptocurrencies.

But while these attacks were very popular last year, this year, the number of SIM swapping attacks appeared to have gone down, especially after law enforcement started cracking down and arresting some of the hackers involved in these schemes.

Something happened last week

But despite a period of calm in the first half of the year, a rash of SIM swapping attacks have been reported in the second half of May, and especially over the past week.

Several users tweeted their horrific experiences.

Some of them have publicly admitted to losing funds, such as Sean Coonce, who penned a blog post about how he lost over $100,000 worth of cryptocurrency due to a SIM swapping attack.

Some victims avoided getting hacked

Some other victims candidly admitted to losing funds, while others said the SIM swapping attacks were unsuccessful because they switched to using hardware security tokens to protect accounts, instead of the classic SMS-based 2FA system.