SEC_Touchpad - How to getrid of it?

My partner has a Samsung A55 phone running Android 16, version 8.5
This evening, he was reading a news item on the internet , using the Samsung browserwhen a floating app called SEC-Touchpad appeared on the screen and won't go away!
It will move about the screen but it appears impossible to close or de-instal it so it intrudes on everything he attempts to do.
He hasn't installed any new apps or had any recent updates so the inference is that this is malware delivered via an ad in the item he was reading.
We have tried rebooting the phone to no effect and the only information we've found on the internet relates to this app in use with gaming programs on Microsoft devices.
Has anyone else encountered this thing, please and can tell us how to get rid of it without doing a factory reset?
Thanks in advance.