Echo the "definitely mold" consensus... (but it sounds like that's already settled)
I've had two mold experiences, and I'm pretty comfortable with my actions and the outcome, so I'll blab on for a minute.
First, I had two Anejos with mold. They came from a holiday sampler. I only checked them in the first place because I read another post written by someone with moldy Anejos. Pulled of the cello and cedar sleeves, and sure enough... mold! D'oh! I wiped 'em clean with a SLIGHTLY (and I mean slightly) dampened paper towel, replaced the cedar (but didn't bother with the cello), and stuck them back in the humi, checking them daily for a little while to see if any mold redeveloped. It didn't. I think I ended up smoking them fairly soon after that, just for the heck of it.
Second (and this was actually earlier), I had a box of H. Upmann Naturales Tubos that I bought in a clearance from TNT cigars. (My second box purchase ever, I think... $40 or so.) Those were narrow (38 RG?) cigars. Actually, pretty darn good for what I paid. Anyway, I smoked one or two (mold free), then sorta neglected the rest of the box for a while... they were in a small coolerdor, but I was a newb, and I think I overhumidified it for a while. Then, I moved them to a better coolerdor setup, but didn't open another tubo for months. All the other non-tubo cigars in the coolerdor were fine, and not a trace of mold. I was then gifted a cigar at some point, and noticed it had a few tiny mold spots, so I did a status check on the rest of the humi. So, I opened up one of the neglected tubos... after several months, and MOLD MOLD MOLD. And not small amounts. I checked the rest of the Upmann tubos... and they all had mold. Some, just a bit, others quite a lot. Several of them had plenty of mold around the foot.
So... at that point, I read a bunch of posts. I wiped off all the mold from the tubos, threw away the tubes, clipped 1/4"-1/2" off the cigars with moldy feet, and put 'em back in the humidor. I did watch the humidor for a while, but there was no recurrence, and the cigars were just fine.
And I just remembered another thing! (A third mold experience.) I actually overseasoned a humi once, lol. Put a little tub of water in there and left it for a week or two (it was just a neat little humi I didn't really need to use, which is why I forgot about it)... and when I opened it up again, it had quite a bit of pure white mold in it. I wiped it out, and let it dry out a bit before re-seasoning it (and paying attention to it, lol). Without using any PG or other "mold fighting" solution at all, it was fine.
SO... my advice is, if you only bought one or two, wipe 'em off, clip a bit of the foot (1/4" should do it), and watch them for a few days... or just smoke 'em, lol! I wouldn't re-cello them myself... I personally think that cello, while breathable, is not "as breathable" as, well... nothing. If you bought several of them (more than two), I'd try to take 'em back, as I'd rather have "perfect" Anejos than slightly clipped ones, heheh. If mold weren't in the foot, I wouldn't even bother to take 'em back.
Finally, as someone else commented, don't worry about "infecting" your other cigars or humi. The spores that start mold are already everywhere, and are in your humi right now. So long as the conditions are kept at 70% (or less), mold should not form (or reform).
Good luck! And again... having a bit of mold on a nice cigar is just a great excuse to hurry up and smoke it!