EMZETT.Data Manipulation
In short: Data manipulation is the unauthorised changing of data, for example numbers, accounts, logs or files.
In more detail: It violates integrity (see CIA triad). Attackers change values to gain advantages or cover their tracks.
In Depth
Examples
SQL injection that changes prices in a database; a man-in-the-middle attack that alters transfer data; deleted or forged log entries.
Countermeasures
Input validation, permission concepts, hashes and signatures for files, audit logs (audit log), backups. In Germany, data alteration is punishable under § 303a StGB.