General
Find the sites
Winter Nexus data-hacking signatures spawn in systems affected by volatile ice storms in HS, LS and NS.
LS sites are assumed to be the most valuable ones, followed by NS and then HS.
Exactly 30 minutes after a site despawns (shortly after hacked), a new signature respawns in the same system.
Difficulty
HS sites can be upgraded by depositing a Cryostatic Estimator (from Yoiul LADs) into Sansha's Stormfield Projector, upgrading the site (increased difficulty & better loot)
LS sites can be upgraded with a Cryostatic Nullifier
NS sites can be upgraded with a Cryostatic Suppressor