I don't know what is recorded in aswAr1.log, so I can't say why it might be being created or if there is a setting that will stop it from being created. I have never had this file created on my current system.
Try Program Settings, Logging and set the Log file size limit to something more bearable, I have mine set at 128 KB even double or quadruple that would be more than adequate and still take up much less scace.
I don't know if you have the Program Settings, Report File option enabled (or even if this would have anything to do with the anti-rootkit), but that gives a different file name in the Report sub-folder. It has an option to overwrite existing report file, rather than adding to the existing one. Again I don't feel this is anything to do with your issue.
Whilst it is relatively small try opening it with wordpad and see what is in it.