The idea that these companies escape scrutiny because of a $1k donation is truly silly. Think harder about this.
The $1k is just an understanding that says "we provide a somewhat unsavory but necessary service to the country (with pretty shitty service to boot) -- it might not be hard for you to kill us (we're not popular and could easily be scapegoated for any number of crimes) but unless you replace us with something better in the process you will risk creating chaos and then voters will toss you out".
The actual money used by the corporate entity Equifax toward election campaigning is unknowable thanks to Citizens United - for example, Equifax could independently fund as many attack ads against as many political candidates as it would like, without reporting any of that spending to the FEC, as long as it does not coordinate with candidate committees.
Even if we assume there is no additional benefit to a candidate aside from the $1k contribution on paper, keep in mind most of this comes from Equifax employees with individual contribution limits - note that the CEO and every VP/high exec contribute the maximum $2700/$5000 limit each cycle.
The $1k is just an understanding that says "we provide a somewhat unsavory but necessary service to the country (with pretty shitty service to boot) -- it might not be hard for you to kill us (we're not popular and could easily be scapegoated for any number of crimes) but unless you replace us with something better in the process you will risk creating chaos and then voters will toss you out".