[publius911]

It would take months to find the code insertions.

Not if you had secured copies of the latest total system software every time it is modified.

In addition, I remember clearly that even in the DOS era, there was always available at least one utility which compared two files bit for bit, to verify exact copies, with no modifications of any sort.

[blackdog]

I make backups every Friday. Those are of the programs of on-line files which then become catalogued in my off-line files. Those are of the program data and configurations. The actual proprietary processor systems programs are Rockwell, Siemens, Robox, Mitsubishi, Danfus, etc......

I cannot run compare scans of file A to file B other than the data. The structure is not available to me. I would have to dump the entire on-line program, replace the processor to be safe, download the OEM software program with my set of keys, then download my saved off-line files, and then re-tweak every machine adjustment.

Alias tagging has become so common now that one corrupted machine file can stop an entire facility. New installations don't even have a run local option anymore!

[blackdog]

My brother in law works as an independent contractor for banks. He runs algorithms to find deposit and debit errors when their daily books don't reconcile. He is always very, very busy. One of the really nifty tricks bi corporations use is to apply all the bad checks they have received to an account where they "accidentally" goof up the account number. Some poor slob has no idea his account is overdrawan to the tune of $130,987.62 for a week. They eventually get it where it belongs but not until p&l bonuses are paid.