Resolved Strange behaviour of my MacBook due to Malware or similar?!?

[VolliK]

Hi all,
I have observed some strange behaviour of my MacBook. May be someone has a good idea where to find the reason:

Here is the story:
I have usually at home a wlan speed of up and down 400mbits/s. Now, on my new MacBook I barely get to 100mbit down and 10mbit up.
However,
-- the above is true only(!!) for my usual personal account ("vok").
-- when I log into another account on my MacBook, speed is normal, no matter if I am logged into vok as well or not. If there is a process running under vok that sits on the wlan port then it does not seem to affect the other accounts.
-- when I use my old MacBook, speed is also fine.

In other works, the problem is local to my vok account.

Here, in sweden, we have this nice speed measuring website http://www.bredbandskollen.se. This site works fine on all accounts except for the vok account where it impacts Safari, Firefox and Chrome. The browsers do not directly crash but, e.g., in case of safari, "Safari Networking" seems somehow affected: I can start using Safari again after I have killed the process.

/Library/Internet Plugins is empty.

I find this all rather weird.

Does anyone have a good idea where to look for the reason?

Thanks in advance
Volker

 

[VolliK]

never mind, it was the iCloud relay that slowed things down...

 

[Isamilis]

Been using Mac for around 15 years, it’s very unlikely to have malware or virus, as long as careful on giving password to allow process / apps installation.