Disk-analyses does use a unique identifier in the IPF container to distinguish IPF generated with it from the official releases. Of course anyone could change it and attempt to create fakes.
The following is an excerpt from the IPF container.
/* crc32("User IPF") -- Arbitrary ID for identifying generated IPFs.
* This is stamped into the INFO release, revision, and userid fields.
* ** IMPORTANT **
* Please respect the SPS and do not change these field values. They are of no
* interest to the IPF decoder library, but allow our IPFs to be easily
* distinguished from preserved images from the SPS library. */
#define IPF_ID 0x843265bbu