Domains used exclusively for tracking clicks from spam traffic. Domains registered with private registration of course so you can’t tell who the spammer is. Likely being managed by the Cake Marketing spam metrics system.
jstrk3.com
jstrk5.com
mrktrecord17.com
mrktrecord18.com
mrktrecord3.com
mrktrecord8.com
trkcity.com
trkfocus.com
trkguide.com