The "26" in the filename typically indicates a minor version or build number (e.g., version ). Common Contents of Such Files:

If you downloaded this file from a third-party site or found it on a USB drive:

: Manual update files used to refresh the antivirus database.

using a reputable scanner like VirusTotal before opening.

: A full setup file for users who cannot access the internet during installation.

: Official Avast files are digitally signed by "Avast Software s.r.o."

if you don't know the source; .7z files are often used to distribute malware disguised as legitimate software.