SIM Swappers Are Using RDP To Directly Access Internal T-Mobile, AT&T, and Sprint Tools

An anonymous reader quotes a report from Motherboard: Hackers are now getting telecom employees to run software that lets the hackers directly reach into the internal systems of U.S. telecom companies to take over customer cell phone numbers, Motherboard has learned. Multiple sources in and familiar with the SIM swapping community as well as screenshots shared with Motherboard suggest at least AT&T, T-Mobile, and Sprint have been impacted. The technique uses Remote Desktop Protocol (RDP) software. RDP lets a user control a computer over the internet rather than being physically in front of it. It’s commonly used for legitimate purposes such as customer support. But scammers also make heavy use of RDP. In an age-old scam, a fraudster will phone an ordinary consumer and tell them their computer is infected with malware. To fix the issue, the victim needs to enable RDP and let the fake customer support representative into their machine. From here, the scammer could do all sorts of things, such as logging into online bank accounts and stealing funds.

This use of RDP is essentially what SIM swappers are now doing. But instead of targeting consumers, they’re tricking telecom employees to install or activate RDP software, and then remotely reaching into the company’s systems to SIM swap individuals. The process starts with convincing an employee in a telecom company’s customer support center to run or install RDP software. The active SIM swapper said they provide an employee with something akin to an employee ID, “and they believe it.” Hackers may also convince employees to provide credentials to a RDP service if they already use it. Once RDP is enabled, “They RDP into the store or call center [computer] […] and mess around on the employees’ computers including using tools,” said Nicholas Ceraolo, an independent security researcher who first flagged the issue to Motherboard. Motherboard then verified Ceraolo’s findings with the active SIM swapper.