Hmmm.
Very strange behaviour.
I see you can still still access the modem's GUI?
If so, what do you see in Device information?
This is from my modem, using the original BLOB:-
Product type EchoLife HG612
Hardware version VER.B
Software version V100R001C01B028SP10
Firmware version A2pv6C030b.d22g
Batch number BC1P10.028.A2pv6C030b.d22g
System up time 42 days 3 hours 5 minutes 6 seconds
Also, can you still access the xDSL stats in the WAN menu?
If not, can you access the modem via Telnet:-
Telnet 192.168.1.1 (or whatever IP address your modem is using).
If you can access it via Telnet (admin, admin, sh) can you still run the usual commands & receive 'sensible' output?:-
xdslcmd info --pbParams
xdslcmd info --stats
xdslcmd info --show
Have you tried powering the modem completely off & back on again?
If you try running HG612_stats.exe by double clicking it, does it provide any meaningful output?
I suppose it's just remotely possible that your virus checker has flagged up a false-positive & is blocking both HG612_stats.exe & DSLstats.exe whenever they try to access the modem.