# Proxmark3 v4.20728 "Phrack" Released

> New `hf saflok` commands, an in-client MQTT bridge, expanded FeliCa dumping and Lite-S auth, iCLASS privilege-escalation restore/write, and the ability to run system commands from the client.

_2025-09-11_

Version **4.20728**, nicknamed **"Phrack"**, of the [Iceman fork](https://github.com/RfidResearchGroup/proxmark3) of the Proxmark3 is available. This release adds Saflok support, a built-in MQTT client, deeper FeliCa tooling, and several iCLASS workflow improvements for Proxmark 3, RDV4 and iCopy-X users.

## Highlights
- New `hf saflok` commands add support for the Saflok hotel lock ecosystem, a frequently requested target.
- The client gained a full MQTT bridge: the new `mqtt` commands let the client send and receive MQTT messages or JSON files, with preference handling, and a Windows segfault in the MQTT path was fixed.
- FeliCa support expanded with `hf felica liteauth` for FeliCa Lite-S authentication, `hf felica scsvcode` to dump all service and area codes, and partial `hf felica dump` of all blocks from unauthenticated readable services.
- iCLASS restore workflows improved: `hf iclass restore` and `hf iclass wrbl` now support privilege escalation to restore card content via replay when MACs are not supplied.
- New `lf t55xx view` command allows viewing T55xx dump files offline, and `lf t55xx restore` now skips writing block 0 when it is all zeros.
- Added HID Simplex Grinnell 36-bit format with an improved Simplex decoder, plus detection of the PCF7961 chipset.
- `data crypto` now also handles AES-256, and `hf mf info` gained detection of unknown and variant backdoor keys.
- New `!` command runs system commands from inside the client (flagged as potentially dangerous when running as root/sudo).

## Contributors
This release landed thanks to [@iceman1001](https://github.com/iceman1001), [@antiklesys](https://github.com/antiklesys), [@zinongli](https://github.com/zinongli), [@CorySolovewicz](https://github.com/CorySolovewicz), [@doegox](https://github.com/doegox), [@stiebeljoshua](https://github.com/stiebeljoshua), [@q0jt](https://github.com/q0jt), [@virtyvoid](https://github.com/virtyvoid), [@henrygab](https://github.com/henrygab), [@trigat](https://github.com/trigat), and others.

Read the [full changelog and downloads on GitHub](https://github.com/RfidResearchGroup/proxmark3/releases/tag/v4.20728).