A user on BreachForums, who goes by the alias IntelBroker, alleges to have posted UScellular customer data on the forum. The individual claims to have taken the information from a database of 144,000 UScellular customers, stolen by hackers in January 2023.
The post, made on 31 January, had the link to download the entire data tranche. IntelBroker’s present avatar has been active on the forum since October 2022. Its previous targets include Verizon, Autotrader, Volvo, Hilton Hotels, and AT&T.
“We have been made aware of a recent security incident at a former third-party vendor resulting in unauthorized access to now out-of-date UScellular customer data. This data included names, email addresses and other account information for about 52,000 accounts,” said UScellular Media Relations Senior Manager Katie Frey in an email response to The Cyber Express.
According to the company, the data did not include Social Security Numbers, credit card numbers, or other sensitive data, and the relationship with this third-party vendor was for a limited time.
We continue to review this incident and determine our next steps.” 
UScellular and data breach
Established in 1983, the Chicago-based company is the fourth-largest wireless carrier in USA. UScellular serves 4,755,000 customers across in 23 US states, as of the third quarter of 2022. The company was earlier known as United States Cellular and U.S. Cellular.
The company had earlier disclosed in December that it suffered a data breach where its billing system was hacked in the incident, leading to the exposure of personal information of 405 individuals.
The attackers used the information stolen to port some of the affected customers’ numbers. UScellular discovered the breach on December 13, and the investigation suggests that the incident took place between December 13 and 19.
The attackers were able to access customers’ account information, including name, address, phone number, and wireless services details.
The company has reset the security questions, answers, and PIN linked to the impacted customers’ accounts, as well as employee login credentials.
UScellular was in the cybersecurity news for a similar incident in 2021. The breach happened after malware installed on a computer at a company retail store allowed hackers to access protected systems.
The breach, which began on January 4, 2021, targeted several employees with access to the company’s CRM software.
The company did not disclose the specifics of the attack, and the breach notification filed with the Office of the Vermont Attorney General mentioned only that the employees were scammed.
Rising Attack against Telecommunications firms
This is the third major attack against telecommunications firms in a short span of time, beginning from AT&T and Verizon.
In fact, cyberattacks against this industry have become a growing concern in recent years, as they can result in widespread disruptions to critical communication infrastructure.
Threat actors may use a variety of tactics to carry out these attacks, such as exploiting vulnerabilities in network hardware and software, disrupting network operations through distributed denial of service (DDoS) attacks, or stealing sensitive information such as customer data or financial information.
