Dear chuckt,
This must surely be the No.1 type of tale round ye old Camp Fire. Particularly by survivors. 
Obviously the safe answer is to dump it (as suggested by yr nom-de-plume) since you (and we) don’t know where it’s been or possibly “modified”.
From a purely analytical POV, I'm not personally familiar with chorizo re. / preservatives / pH / Aw / typical shelf life / epidemiological history so a few basic points to dwell on regarding the extent of yr potential Russian Roulette.
The IT quoted shelf lives seem to vary enormously depending on process, structure, storage and, maybe, luck.
The intuitive initial fear (particularly due to vacuum) is C.botulinum but maybe specifically inhibited by matrix.
Obvious query - What's on the label ? If no label return to 3rd paragraph.
I daresay there are a few (travelling?) chorizo lovers on this forum who will happily be more adventurously predictive ?
Rgds / Charles.C
PS just as a random example -
Chorizo
Chorizo is a spicy pork sausage that comes in many forms. It can be fresh, cured or smoked. It can be seasoned with various chili powders, sweet paprika or smoked paprika. It is made in Spain, Portugal, France and Mexico and each country boasts many varieties of the much adored encased meat. Chorizo is usually reddish-brown in color, but a green chorizo made on the Iberian Peninsula makes use of tomatillos and green chilies. If you’re a chorizo novice, just look for small-production chorizos with packaging that reveals their country of origin.
- Judging freshness. If you spy mold, the chorizo has got to go. Depending on the variety (cured vs. fresh), chorizo’s shelf life can range from 1 to 6 weeks, so use common sense when picking out your sausage of choice.
- Storing at home. Fresh chorizo should be wrapped tightly and can be refrigerated for up to a week. Cured and smoked chorizo will last this way for up to a month.
(my underlines )
http://www.cooktaste...edients/chorizo
