Error message: wp-sleeeps/wp-sleeeps.php on line 26 (Hacked?)

Immediate assistance is available at 04122/9669868. Yesterday at 6:10 PM (December 26, 2020), we received the following error message on a WordPress website: wp-sleeeps/wp-sleeeps.php on line 26. The WordPress site is redirected to https://studentswimcorn-5.live/ and a message from Telekom appears, for example: Dear Telekom (T-Mobile) @C customer! We would like to thank you for your trust in Telekom (T-Mobile) @C and therefore…