Reasonable Response by TSMC
It seems TSMC did the correct things in response to this.
Following claims by ransomware gang LockBit that it has stolen data belonging to TSMC, the chip-making giant has said it was in fact one of its equipment suppliers, Kinmax, that was compromised by the crew, and not TSMC itself. On Thursday, the gang claimed on its website that it had managed to break into TSMC's systems, and …
Ah, like my "diagnostics" flash drive. I use a SDMMC card in a card-to-USB converter.
Caution #1: The executing OS might be compromised; if it is, just reboot. The source OS probably won't be compromised (see below).
Caution #2: Many SDMMC-card-to-USB converters ignore the "read-only" switch on the SDMMC card. I had to buy quite a few converters 'till I found one which did/does respect the lock switch.
Caution #3: SDMMC-card-to-USB converters contain a microcontroller, which may be compromisable. Using a CDROM or DVD burned in TAO mode and run from a portable drive would be safer, though less-convenient.