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Defeating a Laptop's BIOS Password

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Re: Defeating a Laptop's BIOS Password

#91

Post by ineedasername »

da_chicken wrote: post #84
ineedasername wrote: post #81

Way back in the first years of the 00's, working IT support in college, BIOS passwords were common (though not mandatory) on the Faculty/Staff desktops. So, forgetting passwords was common as well, and at the time we could reset them by opening them up and swapping a jumper to another set of pins. It struck me as fairly useless to have a BIOS password at the time. Forever after, on bootup, "Warning! Case has been ope…

The BIOS should have a reset option for the case open switch. It's just a warning you toggle off in the BIOS. The idea is that only a tech would know the BIOS password to turn it off, so that's how you know that someone knows about it. It's also unusual that discharging the CMOS removed the boot password. It shouldn't do that. I also worked on similar desktops (they were IBM desktops from before they were spun off) a…

They were Compaqs at the time, but if I recall correctly, we switched to Dell at one point and it was pretty much the same situation.

Re: Defeating a Laptop's BIOS Password

#92

Post by Avery3R »

mafriese wrote: post #67

can someone tell me which flash programmer is used here? I also want to play around with UEFI.

We used J-Link with a J-Flash SPI license. https://www.segger.com/products/debug-probes/j-link/tools/j-...

Any SPI flash programmer should work though. The protocol is simple enough that you could even implement it with an arduino if you really needed too.

Re: Defeating a Laptop's BIOS Password

#93

Post by winternett »

big_chungus wrote: post #85
sph wrote: post #68

I "cracked" my father's laptop's password when he passed away 15 years ago by buying a similar, broken laptop on eBay for cheap, and unsoldering and switching the ROM/EEPROM containing the BIOS. Probably one of the coolest things I've done as a teenager.

Why re-solder the chip? It seems as though it would be easier to recover data by just yanking the drive, especially since full-disk encryption was quite rare fifteen years ago. Failing that, couldn't you have used a SPI flasher with the existing chip?

Can't you still just remove the battery on the mother board for a few seconds? I used to do that all the time back when I was a repair tech...

Re: Defeating a Laptop's BIOS Password

#94

Post by hunter2_ »

da_chicken wrote: post #84
ineedasername wrote: post #81

Way back in the first years of the 00's, working IT support in college, BIOS passwords were common (though not mandatory) on the Faculty/Staff desktops. So, forgetting passwords was common as well, and at the time we could reset them by opening them up and swapping a jumper to another set of pins. It struck me as fairly useless to have a BIOS password at the time. Forever after, on bootup, "Warning! Case has been ope…

The BIOS should have a reset option for the case open switch. It's just a warning you toggle off in the BIOS. The idea is that only a tech would know the BIOS password to turn it off, so that's how you know that someone knows about it. It's also unusual that discharging the CMOS removed the boot password. It shouldn't do that. I also worked on similar desktops (they were IBM desktops from before they were spun off) a…

> HP had a similar program, but that stopped working around 2010

Can I obtain this somehow? I have a business grade HP laptop from 2006 (nw8440 I think) and I forgot my BIOS setup password. I need to enable the NX bit to upgrade from win7 to win10! Removing the CMOS battery overnight (and all other power) did not help.

Re: Defeating a Laptop's BIOS Password

#95

Post by 1_player »

winternett wrote: post #93
big_chungus wrote: post #85

Earlier quoted context omitted.

Why re-solder the chip? It seems as though it would be easier to recover data by just yanking the drive, especially since full-disk encryption was quite rare fifteen years ago. Failing that, couldn't you have used a SPI flasher with the existing chip?

Can't you still just remove the battery on the mother board for a few seconds? I used to do that all the time back when I was a repair tech...

EEPROMs are non-volatile. They don't need power to keep their data. AFAIK removing the battery just resets the real time clock.

Re: Defeating a Laptop's BIOS Password

#96

Post by 1_player »

big_chungus wrote: post #85
sph wrote: post #68

I "cracked" my father's laptop's password when he passed away 15 years ago by buying a similar, broken laptop on eBay for cheap, and unsoldering and switching the ROM/EEPROM containing the BIOS. Probably one of the coolest things I've done as a teenager.

Why re-solder the chip? It seems as though it would be easier to recover data by just yanking the drive, especially since full-disk encryption was quite rare fifteen years ago. Failing that, couldn't you have used a SPI flasher with the existing chip?

To a teenager with only a passing experience with electronics, operating a soldering iron is much easier than learning to flash an EEPROM :-)

And I only had one working, locked laptop and a broken one. The whole endeavour was mostly to inherit my father's laptop than to recover any data. What I did with my father's data is probably a story for another time.

Re: Defeating a Laptop's BIOS Password

#97

Post by shakna »

hunter2_ wrote: post #94
da_chicken wrote: post #84

Earlier quoted context omitted.

The BIOS should have a reset option for the case open switch. It's just a warning you toggle off in the BIOS. The idea is that only a tech would know the BIOS password to turn it off, so that's how you know that someone knows about it. It's also unusual that discharging the CMOS removed the boot password. It shouldn't do that. I also worked on similar desktops (they were IBM desktops from before they were spun off) a…

> HP had a similar program, but that stopped working around 2010 Can I obtain this somehow? I have a business grade HP laptop from 2006 (nw8440 I think) and I forgot my BIOS setup password. I need to enable the NX bit to upgrade from win7 to win10! Removing the CMOS battery overnight (and all other power) did not help.

You place a file you _may_ be able to get from support (called SMC.bin) onto a FAT32 USB drive, and then:

1. Power off.

2. Hold the Windows, Up arrow and Down arrow keys all at the same time. Only then hit the power button to start.

3. Release all buttons and press F10.

4. You should see something about "SMC Command" starting.

5. Press File, press "Reset BIOS security defaults" or similar.

The only way to get the SMC.bin file, that I know of, is directly from HP Business Support.

Re: Defeating a Laptop's BIOS Password

#98

Post by mikorym »

diffeomorphism wrote: post #64
mikorym wrote: post #62

Does this also hold for Macbooks? Edit: A more precise question would be: What is the analogy to Secure Boot and the hardware being locked on a Macbook?

Is there anything actually different? A Macbook is a relatively standard Intel laptop that happens to run MacOS. The only additional complication might be the T2 chip in the same way that TPMs might be an additional issue in other business laptops.

I don't know. The reason why I ask this is that I want to replace my Macbook's startup chime with something else.

Re: Defeating a Laptop's BIOS Password

#100

Post by faceplanted »

criddell wrote: post #80
faceplanted wrote: post #72

Earlier quoted context omitted.

If someone has that much physical access to your machine they can capture your password far more easily with a physical keylogger assuming you use an external keyboard like one time.

Or apply rubber hose cryptanalysis. https://xkcd.com/538/

That's not really the same situation, if someone's trying to bug you they don't want to be caught, if they were willing to do illegal violence they'd probably do it first, or if they're a government, you have way bigger problems.
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