A TrueType font is a widely supported font file format used by Windows, macOS, Linux, and many applications to render text consistently. Because it is a normal, familiar file type, attackers may use font-themed attachments or filenames to make a message look routine and harmless.
In cyber security, TrueType fonts matter because trust in a file type can lower suspicion before a user opens it. A malicious campaign may disguise another payload as a font file, or, in some cases, try to make a real font file reach a vulnerable parsing path on the endpoint. Defenders reduce this risk by verifying file extensions and MIME types, filtering unexpected attachments, and blocking untrusted fonts where policy allows. Treating unusual font files as suspicious helps stop both social engineering and potential parser-based exploitation.