Esta parece ser uma característica normal do sistema. Um tópico foi aberto nos fóruns da Kali sobre um problema semelhante, eles não encontraram o pacote culpado, mas o problema foi encerrado, já que é uma característica normal do sistema que parecia emitir os pedidos. Referência: link
Se eu fizer um tcpdump:
sudo tcpdump port 8612 -XXX
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on wlo1, link-type EN10MB (Ethernet), capture size 262144 bytes
14:41:08.463778 IP Computer.8612 > 192.168.1.255.8612: UDP, length 16
0x0000: ffff ffff ffff 184f 3291 3f81 0800 4500 .......O2.?...E.
0x0010: 002c 9242 4000 4011 e9c9 c0a8 1e65 c0a8 .,.B@[email protected]..
0x0020: 1eff 21a4 21a4 0018 6b25 424a 4e50 0201 ..!.!...k%BJNP..
0x0030: 0000 0000 0000 0000 0000
........
Você vê o k% BJNP?
Acontece que o BJNP se refere a impressoras Canon.
Se eu desinstalar o libsane, não vejo mais a porta 8612 sendo bloqueada no firewall se eu conectar uma unidade USB:
May 19 14:53:27 Device3 kernel: usb 2-3: new high-speed USB device number 11 using xhci_hcd
May 19 14:53:29 Computer kernel: usb 2-3: New USB device found, idVendor=048d, idProduct=1177
May 19 14:53:29 Computer kernel: usb 2-3: New USB device strings: Mfr=1, Product=2, SerialNumber=0
May 19 14:53:29 Computer kernel: usb 2-3: Product: USB Mass Storage Device
May 19 14:53:29 Computer kernel: usb 2-3: Manufacturer: Generic
May 19 14:53:29 Computer kernel: usb-storage 2-3:1.0: USB Mass Storage device detected
May 19 14:53:29 Computer kernel: scsi host2: usb-storage 2-3:1.0
May 19 14:53:29 Computer mtp-probe[9600]: checking bus 2, device 11: "/sys/devices/pci0000:00/0000:00:10.0/usb2/2-3"
May 19 14:53:29 Computer mtp-probe[9600]: bus: 2, device: 11 was not an MTP device
May 19 14:53:32 Computer kernel: scsi 2:0:0:0: Direct-Access Generic USB Flash Disk 0.00 PQ: 0 ANSI: 6
May 19 14:53:32 Computer kernel: sd 2:0:0:0: Attached scsi generic sg0 type 0
May 19 14:53:32 Computer kernel: sd 2:0:0:0: [sda] 31459328 512-byte logical blocks: (16.1 GB/15.0 GiB)
May 19 14:53:32 Computer kernel: sd 2:0:0:0: [sda] Write Protect is off
May 19 14:53:32 Computer kernel: sd 2:0:0:0: [sda] Mode Sense: 23 00 00 00
May 19 14:53:32 Computer kernel: sd 2:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
May 19 14:53:32 Computer kernel: sda: sda1
May 19 14:53:33 Computer kernel: sd 2:0:0:0: [sda] Attached SCSI removable disk
May 19 14:53:34 Computer kernel: EXT4-fs (sda1): recovery complete
May 19 14:53:34 Computer kernel: EXT4-fs (sda1): mounted filesystem with ordered data mode. Opts: (null)