Media reports say a major Russian telecommunications provider, Rostelecom, is investigating a suspected cyberattack on one of its contractors after hackers claimed to have leaked the company's data.

Earlier on Tuesday, the hacker group, which calls itself Silent Crow, published a data dump containing thousands of customer emails and phone numbers allegedly stolen from Rostelecom.

The Record says the company stated that the contractor is responsible for maintaining Rostelecom’s corporate website and procurement portal, both of which were reportedly targeted by hackers.

“We're currently reviewing the database to determine which data was compromised and whether it’s related to the company,” Rostelecom was cited as saying in a comment to state-owned media.  “Based on initial findings, it appears that there wasn’t any leak of highly sensitive personal data.”

However, as a precaution, the company advised users of the allegedly hacked websites to reset their passwords and enable two-factor authentication.

In response to the incident, the Russian Ministry of Digital Development stated that the breach did not impact the state services portal and that no sensitive data from the operator's subscribers had been leaked online.

"Today a hacker attack was made on the infrastructure of the contractor "Rostelecom". It did not affect in any way "Gosudservices". All data of the portal is under reliable protection. Sensitive personal data of private clients of the contractor company also did not leak out," the ministry said in its Telegram channel, according to Izvestriya.

Silent Crow has unclear origins and motives.  It publishes leaks on a private Russian-language Telegram channel, but without demanding ransoms from victims.  Earlier in January, the group claimed responsibility for breaching a Russian government agency, Rosreyestr, which manages property and land records.  The agency denied the hack but confirmed it is investigating the group’s claims.

The cyberattack on Rostelecom is one of the latest against prominent Russian organizations in recent weeks.

The Record reports that earlier this month, Russia’s main electronic trading platform for government and corporate procurement, Roseltorg, confirmed its systems had been breached by an unknown pro-Ukraine hacker group called Yellow Drift.

Another hacker group, the Ukrainian Cyber Alliance, also claimed responsibility for an attack on the Russian internet provider Nodex, stating that it had destroyed the company’s infrastructure overnight. Nodex confirmed the attack.

A Ukrainian hacker group called Cyber Anarchy Squad announced it had attacked the Russian tech company Infobis, which develops systems for planning, monitoring, and accounting agricultural work.  The hackers claimed to have exfiltrated three terabytes of information and destroyed part of the company’s infrastructure.

Russian businesses and state agencies are reportedly becoming increasingly aware of cybersecurity dangers that they face.  The local internet regulator, Roskomnadzor, registered 135 cases of database leaks in 2024, containing more than 710 million records about Russian citizens.