Users of the macOS Telegram messaging app are being warned about possible problems privacy that could expose files shared with other users.

According to research by Reegun Richard Jayapaul, who is the lead threat architect at Trustwave SpiderLabs, the ability to delete an application that focuses on privacy can be bypassed and the files kept permanently.

The first issue was that all multimedia files sent via Telegram were stored in a cache, even after a message self-destructed.

This means that a hacker could still access these files (audio, video, shared sites or documents), according to Jayapaul. It is also the second time this year that a researcher has found that files were not deleted effectively when deleting conversations in the Telegram application.

A second issue that was also not fixed by Telegram by deleting the messages is that it gives the hacker the ability to bypass its security devices, by simply stealing a file from the cache folder without the recipient ever opening it.

This could, of course, be done with λήψη snapshots screen or recordings, although the cached entry indicates to the sender that the recipient has not read the message, leaving them completely unaware.

"With the help of researchers, we continue to improve the functionality and security of features like this," Telegram said.