Unperseable JSON value for the Bulk Export of activity - Unsubscribe Email/Fill Out Form

Getting unparseable json for the attribute "Form Fields"  while calling API for the activity - Unsubscribe Email/Fill Out Form.

Example-

ActivityTypeId - 2,9

API - /bulk/v1/activities/export/{exportId}/file.json

method - GET

Response - CSV

 This contains one column called - "attributes" which contains below json-

{
   "Client IP Address": "Masked IP",
   "Query Parameters": "",
   "Referrer URL": "Masked URL",
   "User Agent": "Masked User Agent",
   "Webpage ID": 1,
     "Form Fields": "a:5:{s:6:\"module\";s:11:\"something\";s:6:\"action\";s:5:\"some action\";s:9:\"FirstName\";s:6:\"Some       First Name\";s:8:\"LastName\";s:5:\"Some Last       Name\";s:13:\"_mktoReferrer\";s:59:\"https://some.something.com/abc.html\";}"
}

• Please let us know how to parse this value of Form Fields to a json.
• Is there any parser or sample code available in marketo for this?