I have an example of a run my GM threw at us recently.
We were hired by a Johnson to go in and add several lines of pre-generated code to a specific file on a Corp server located in downtown Seattle. The company name was pretty non descript: Atherton Enterprises, so at first we didn't think anything of it. The run came with all the usual caveats: No death count, no noise, no alarms. They wanted no one to know that the file had been tampered with. The job had to be completed in the next 5 days.
For our team, this is right up our alley, as 3/4 of the team is about infiltration. (the other 1/4 is all about maximum firepower, but they are not totally inept at stealth either)
SO we got to work with the usual legwork. Background checks on Johnson so we know exactly who or what we are dealing with when the run is over. Background, company history and specialty of Atherton Enterprises. Scoping out the building and security, and finally examining the code pack we were to insert. (you don't actually trust your Johnsons, do you?!?!?)
The Johnson was just that, a Professional talent scout for a AAA Corp by association. (For a Medtech Corp, owned by NeoNet)
Atherton Enterprises turned out to be a real hassel to track back, but we eventually discovered that it was a private Corp, owned by a Louise Atherton, and it was involved Cancer research.
The building new, but the security was actually very sub-par. Atherton Enterprises had very little extra security that the building owners didn't supply, and the supplied security was... marginal.
The code pack was a huge puzzle for our Techno to pull apart and figure out what it was to do. But eventually she worked out that it's only purpose was to invert some numbers in a complex formula, but hid the inversion from being noticed. What this would do, we had no idea.
Getting in and into the secured computer was more of a challenge then we thought (Nothing goes as planned. EVER.) but we got our techno in and she went to work - or so we thought. While we were all sitting on our thumbs covering her for what should have been a 10 minute job, ended up taking 30 minutes (requiring the team to improvise several distractions to keep security from finding her, but not so much of a distraction that it raised alarms.) Turns out she was studying what the code packet would do, and what the file was about and not actually inserting it!
Turns out that Atherton Enterprises had figured out a treatment for childhood lymphoma that increased survival rates to 95% even if treatments were started in the second stage the cancer progression. The code packet changed the treatment and made it toxic. So toxic that it would actually speed up the progression of the cancer and make it untreatable. To make matters worse, it was scheduled for human testing the next month after having completed animal and simulation testing the previous year. There was 10,000 kids lined up to be treated with the drug in the next 6 months.
Once we found out, we walked out. refunded 75% of the deposit, and told the Johnson to never contact us again.