Can a .3mf file have a virus?
A .3mf is a ZIP of XML and pictures. It does not run by itself, so it cannot
infect a computer the way a program can. The real risks are a bug in the app
that reads it, and custom G-code your printer will run.
Has a .3mf ever run code on a computer?
Yes, through slicer bugs, each fixed since:
| Case | App | Fixed in |
|---|---|---|
| CVE-2024-8374 | UltiMaker Cura 5.7.0-beta.1 to 5.7.2 ran a metadata value through Python eval() (advisory) |
Cura 5.8.0 |
| CVE-2020-28594 | PrusaSlicer 2.2.0 freed memory and then used it while reading a crafted file | Later releases |
| CVE-2021-21772 | lib3mf 2.0.0, the 3MF Consortium's reader, had the same kind of memory bug | lib3mf 2.0.1 and 2.1.1 |
Each needed an out-of-date app. None of them work on a current release. See code injection for the Cura case.
Can a .3mf damage my printer?
A project can carry custom start, end and layer G-code, and the printer runs
it as written. A wrong bed temperature, a move off the bed, or M500, which
saves settings to the printer's memory, would all happen for real. Bambu
Studio and OrcaSlicer warn when a project's G-code differs from the system
preset; see the 3mf has modified G-codes.
What about a download that is not a .3mf?
That is where real malware turns up. In 2026 a MakerWorld download held a
.blend file and an .exe with an AutoHotkey script, and no 3MF or STL at
all
(forum thread).
Never run a program that came with a model download.
How do I check a .3mf before I slice it?
- Drop it on preslice.co. It is read inside the browser tab and nothing in it runs.
- Open the Security tab. It checks for six known attack patterns, from XML tricks to file names that escape their folder.
- If the slicer warns about modified G-codes, read them in the Raw tab first.
See the Security tab for what each check means.
What keeps me safe in general?
Keep your slicer updated, since every known case was fixed in a later release.
Read the modified G-codes warning instead of clicking past it. Download
models from the designer's own page, and treat any .exe, .bat or .scr in
a model download as malware.
Is preslice an antivirus?
No. It checks for attacks aimed at 3MF readers, and it does not verify signatures or scan for viruses in general.