A torrent comes from other people's computers, not from one website. That changes what you can trust and what others can see. This page says plainly what MDM does and what it doesn't. The switches it mentions are in Tasks → Torrent settings....
What other people can see
- Your IP address. Everyone sharing the same torrent sees it, as do its trackers and the DHT (the network peers use to find each other). That's how BitTorrent works, and no setting in MDM changes it. To hide your address, use a VPN on your whole computer.
- What you download, on your local network. MDM tells other computers on your network which torrents it has, so they can share faster. On public Wi-Fi, turn off Find peers on the local network.
- That you use MDM. Peers see the name "MisterDownloadManager" and its major version, not the exact build.
MDM's torrents don't use encryption (sometimes called "protocol encryption"). That kind of encryption only hides the traffic from simple filters. It never hides who you are, so MDM doesn't claim to offer it. Some peers that require it won't connect.
What reaches your computer
MDM starts its torrent engine the first time a torrent needs it. With Stop the torrent engine when no torrent is running on (the default), it stops again a minute after no torrent is running or sharing. While it runs, other peers can connect to MDM, and MDM asks your router to forward its port (UPnP). Windows may ask whether to allow MDM through the firewall: allow it on private networks only.
In Torrent settings you can turn off Accept incoming connections and Map the port on the router (UPnP), or the DHT. Downloads still work, sometimes more slowly. A fixed Port keeps firewall and router rules working. These changes apply the next time the engine starts, so when no torrent is running.
The torrent engine is written in Rust, which rules out many memory bugs, and MDM checks every piece against the torrent's fingerprint, so a peer can't slip in altered data. MDM keeps the engine up to date with the fixes its authors publish.
Trackers
A torrent names the trackers MDM asks for peers. MDM doesn't contact a tracker on your own computer or your local network (127.0.0.1, 192.168.…, localhost and the like), so a torrent can't make MDM send requests into the network it sits in.
Blocking addresses
Block the addresses in this list takes the address of a public IP blocklist, in the P2P (PeerGuardian) or eMule .dat format, plain or gzipped. MDM downloads it with its own downloader (your Proxy / Socks settings apply), checks it, and fetches it again every 7 days. Peers in it are refused. A list MDM can't read is left out, and the last good one stays. The engine reads the list when it starts.
Files from a torrent
- MDM refuses a torrent with file names your system can't write safely, says which name, and writes nothing.
- MDM never writes into a file that's already there without asking.
- Files from torrents are marked as downloaded from the internet, like a browser's downloads. Windows SmartScreen checks a program before it first runs, and Office opens documents in Protected View. On a Mac, Gatekeeper checks apps.
- A torrent can contain anything, and anyone can make one. Only open programs from people you trust, and scan them if in doubt.
Proxies
MDM's Proxy / Socks settings are for web and FTP downloads. Torrents can use a SOCKS5 one too: set a socks5:// proxy in Options → Proxy / Socks and turn on Use the proxy in Torrent settings. The proxy covers connections to peers and web trackers only, so with it MDM turns off the DHT, local peer discovery, incoming connections and UDP trackers. If the proxy is gone from Proxy / Socks while that switch is on, torrents don't start rather than go around it.
To route everything through another network, use a VPN for the whole computer. MDM can't tie torrents to one network adapter on Windows.
Reporting a problem
Found a security issue? Please report it privately on GitHub (Security → Report a vulnerability, see SECURITY.md) rather than in a public issue.
Next steps
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