I can pretty much guarantee that the moisture got in through the 17-70 which isn't weather sealed. Pentax cameras are only 'weather resistant' when paired with 'weather resistant' WR or DA* lenses.
Most lenses have a soft velvety cloth or foam seals on extending barrels to help them slide and keep out dust, but they can quickly soak up water. Even a few drops on the extending barrel of the 17-70 can make their way inside, especially when you zoom / retract the lens barrel after the drops hit it. When this moisture evaporates later it can make its way into the body or further into the lens. Pentax WR lenses like the 18-135 have a special foam seal that keeps dust out and doesn't absorb the moisture. Even with WR lenses, extending zoom lens barrels still pumps outside air into the lens / camera body when you repeatedly zoom in and out.
Once cooled that humidity can condense, so it's a good idea to pump the zoom a few times in the dry air to replace the humidity in the camera/lens combo. Then, leave the lens and body apart in an air tight box with some desiccant to pull out any remaining moisture. You can get an
airtight storage tote at Target or Walmart for pretty cheap, and reusable desiccants are cheap on
eBay or
Amazon. If you're in a real pinch, a ziploc bag with rice will work as a last resort, but be VERY careful not to get rice dust inside your equipment!