Detecting dataset modification

Dataset modification implies that an external source, hacker, disgruntled employee, or other entity has purposely changed one or more records in the dataset for some reason. The source and reason for the data modification are less important than the effects the modification has on any analysis you perform. Yes, you eventually need to locate the source and use the reason as a means to keep the modification from occurring in the future, but the first priority is to detect the modification in the first place. Consider this sequence of events:

1. Hackers want to create an environment where products from Organization A, a competitor of Organization B, receive better placement on a sales site because the competitor is paying them to do so
2. The hackers discover that buyer product reviews and their product ratings are directly associated with the site’s ranking mechanism
3. The hackers employ zombie systems (computers they have taken over) to...