A Data Bank.

Interesting, they have a lot of on-site data banks here. Might be worth a search.
—Central

Data Banks side-missions can occur as an optional secondary objective in typical missions. The objective of a Data Banks side-mission is to find and hack all three Data Banks; the reward for completing the side-mission is a Data Card, which unlocks a datalog and is worth credits.

Data Banks should not be confused with Research Databanks, which have a similar name but are unrelated.

Internationale hacking a Data Bank.

From that sample data packet, traces of Invisible came up. If we've got time, wiping us from all of these drives might be a wise choice. We may even recover some of our stolen archives.
—Central

A Data Bank is a mainframe device, three of which occur in each Data Banks side-mission. To complete the side objective, all three Data Banks must be located and scrubbed. To scrub a Data Bank, Incognita must first capture it, and then an agent on adjacent tile must hack it, which will take 3 turns.

Data Card icon

Scraped from a corporate server as it was wiped, this is a little piece of data that belonged to Invisible, Inc. before the raid.

After the final Data Bank has been scrubbed, it will drop a Data Card. Data Card is a valuable that will yield 500 credits and a random datalog upon completing the mission. Alternatively, Data Cards can be sold at nanofabricators for 500 credits, but it will not unlock a data log, so the former is more preferable. All data logs will be permanently saved.