Due to security flaws in WhatsApp, Telegram founder Pavel Durov stated on Thursday that hackers can acquire complete access to all personal data on users' phones.

"Hackers could have full access to everything on the phones of WhatsApp users. This was possible through a security issue disclosed by WhatsApp itself last week," Durov said on Telegram.

Hackers merely need to transmit a malicious video to a WhatsApp user or start a video call via the app to seize control of a smartphone, according to Durov.

This is not the first time WhatsApp has encountered security concerns, which signals the possibility of future security flaws, according to Durov.

"You can use any messaging app you like, but do stay away from WhatsApp – it has now been a surveillance tool for 13 years," Durov noted.

WhatsApp was fined 225 million euros ($267 million) in September 2021 for violating EU data privacy rules. The Irish Data Protection Commission, which conducted the investigation, noted that WhatsApp failed to inform EU citizens about how it handles their personal data, including how it shares that information with its parent company Meta.

A Russian court fined WhatsApp, Snapchat, and other foreign firms in July for refusing to store Russian users' data domestically.

Moscow has previously fined big tech companies over content, censorship, data, and local representation since the beginning of the special military operation in Ukraine.

Last August, the court ruled that social media giants Twitter and Facebook have to pay 17 million rubles ($227,882) and 15 million rubles ($201,072) respectively for repeated violations of the law, which requires that data on Russian users be stored in Russia. It also for the first time penalized messaging app WhatsApp – owned by Facebook – for 4 million rubles ($53,619) for the same offense.