Re: Have I caught a firmware attack in the act? Or am I just paranoid?

From	"Rebecca N. Palmer" <rebecca_palmer@zoho.com>
Newsgroups	linux.debian.security
Subject	Re: Have I caught a firmware attack in the act? Or am I just paranoid?
Date	2019-08-15 23:20 +0200
Message-ID	<yvvk5-3bf-1@gated-at.bofh.it> (permalink)
References	<yuzzs-7fV-11@gated-at.bofh.it> <yv3xv-1cl-5@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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Paul Wise wrote:
>> but at least some USB flash drives instead use an SCSI command [1],
>> which usbguard won't catch.
> 
> This seems like a significant missing feature, but I guess it would
> require a fair bit of Linux kernel work to support filtering such
> commands.

If the attacker has root (which they need to use either firmware update 
mechanism anyway) on the base system, they've already won: they can 
simply uninstall usbguard or similar tools.

If the attacker is in a VM/container, writing to firmware is a possible 
escape route, but I'm not sure whether usbguard or the VM software is a 
better place to address it.

I think of usbguard as mostly for blocking the device-to-host (not 
host-to-device) direction of infection, specifically devices that 
pretend to be keyboards and "type" malicious commands.

> Based on the serial number deletion, I'd speculate that some internal
> part of the flash holding details about the device identity
> malfunctioned, so the firmware reverted back to the default hardcoded
> product id for Alcor flash drives. No idea if this is a reasonable
> theory or what caused the malfunction, malware or otherwise.

It makes sense for the firmware to have a fixed bootloader part: USB is 
a complex enough protocol that accepting firmware updates over it is 
likely to itself require firmware, and the (different) brand that has 
publicly been attacked does have one:

https://srlabs.de/wp-content/uploads/2014/11/SRLabs-BadUSB-Pacsec-v2.pdf

On 14/08/2019 16:31, Elmar Stellnberger wrote:

> Central 
> intelligence usually does not target Debian software directly. If a 
> malware was distributed via the official release or update service then 
> someone would get to know it and proper antivirus/malware detection 
> software could be written. They will never do so. They only target 
> specific individuals like you

That would suggest it's not them, as the obvious reason to target me is 
to trick me into uploading malware.

>    Have you written something like debcheckroot? If yes I would be 
> interested in it.

https://lists.debian.org/debian-security/2018/02/msg00012.html

The check script is config/includes.chroot/usr/local/bin/integrity_check.py

> debcheckroot is GPL so it could be an option to 
> continue developing it though I did not have the time to do so in the 
> last years. However it currently still uses unsafe md5sum. However I 

Another potential home for this script is tiger, which also currently 
has an MD5-only checker:

https://sources.debian.org/src/tiger/1:3.2.4%7Erc1-1/systems/Linux/2/deb_checkmd5sums/

> It may be more probable that they simply infect a hidden file in 
> your home directory[...]
>    I would presume that you have booted from DVD when checking your 
> installation since it does not make sense to check from within an 
> infected system. That would be going to fail in almost 100% of the cases.

This check was done from within the system (it was never intended to be 
a perfect test - as you note, it can be evaded by infecting a 
non-package-owned file), but my script can also do checking from a DVD boot.

>    There is hardly any way to get a computer safe except when you remove 
> all networking hardware putting the computer offline and then always 
> carry the M.2 drive to boot from with you. It would be a question why 

My GPG keys are offline in that I only insert them after booting from a 
DVD with a no-networking kernel, but as this is on the same physical 
computer (which doesn't have a hardware-level way to disable 
networking), a firmware attack could bypass this.

> I have only 
> seen intelligence visiting my home when I left an offline computer 
> around with HDD.

If you feel safe answering: what country was this in?  Your name and 
time zone suggest Germany/Austria/Switzerland, which I wouldn't have 
thought of as the kind of places that do this.

Though I also wouldn't have thought of Britain as the first place to 
have "help us spy and don't tell anyone, or we'll imprison you" legal 
orders until we were...

https://www.eff.org/deeplinks/2016/02/investigatory-powers-bill-and-apple

...which is one reason I prefer to stay away from maintaining security 
tools or other highly sensitive packages.

Thread

Have I caught a firmware attack in the act? Or am I just paranoid? "Rebecca N. Palmer" <rebecca_palmer@zoho.com> - 2019-08-13 09:40 +0200
  Re: Have I caught a firmware attack in the act? Or am I just paranoid? Paul Wise <pabs@debian.org> - 2019-08-14 07:10 +0200
  Re: Have I caught a firmware attack in the act? Or am I just  paranoid? Elmar Stellnberger <estellnb@gmail.com> - 2019-08-14 17:40 +0200
    Re: Have I caught a firmware attack in the act? Or am I just  paranoid? "Rebecca N. Palmer" <rebecca_palmer@zoho.com> - 2019-08-15 23:20 +0200
      Re: Have I caught a firmware attack in the act? Or am I just  paranoid? Davide Prina <davide.prina@gmail.com> - 2019-08-16 10:40 +0200
        Re: Have I caught a firmware attack in the act? Or am I just  paranoid? CMH <chouck@binghamton.edu> - 2019-08-16 14:20 +0200
        Re: Have I caught a firmware attack in the act? Or am I just paranoid? Andrei Grosu <andrei_grosu@fastmail.net> - 2019-08-16 19:20 +0200
        Re: Have I caught a firmware attack in the act? Or am I just  paranoid? Elmar Stellnberger <estellnb@gmail.com> - 2019-08-16 19:20 +0200
      Re: Have I caught a firmware attack in the act? Or am I just  paranoid? Elmar Stellnberger <estellnb@gmail.com> - 2019-08-16 19:10 +0200
      Re: Have I caught a firmware attack in the act? Or am I just  paranoid? Elmar Stellnberger <estellnb@gmail.com> - 2019-08-16 19:30 +0200
      Re: Have I caught a firmware attack in the act? Or am I just  paranoid? Elmar Stellnberger <estellnb@gmail.com> - 2019-08-16 21:20 +0200
        Re: Have I caught a firmware attack in the act? Or am I just  paranoid? "Rebecca N. Palmer" <rebecca_palmer@zoho.com> - 2019-08-17 11:50 +0200
          Re: Have I caught a firmware attack in the act? Or am I just  paranoid? Elmar Stellnberger <estellnb@gmail.com> - 2019-08-17 13:20 +0200
            Re: Have I caught a firmware attack in the act? Or am I just  paranoid? "Rebecca N. Palmer" <rebecca_palmer@zoho.com> - 2019-08-23 09:30 +0200
              Re: Have I caught a firmware attack in the act? Or am I just  paranoid? Elmar Stellnberger <estellnb@gmail.com> - 2019-08-23 21:00 +0200
                debcheckroot v2.0 released Elmar Stellnberger <estellnb@gmail.com> - 2019-11-15 17:20 +0100
                Verified Boot, Secure Boot, dm-verity, debcheckroot Patrick Schleizer <adrelanos@riseup.net> - 2019-11-16 14:00 +0100
                Re: Verified Boot, Secure Boot, dm-verity, debcheckroot Elmar Stellnberger <estellnb@gmail.com> - 2019-11-16 15:30 +0100
                Re: Verified Boot, Secure Boot, dm-verity, debcheckroot Sylvain Beucler <beuc@beuc.net> - 2019-11-16 15:40 +0100
                Re: Verified Boot, Secure Boot, dm-verity, debcheckroot Elmar Stellnberger <estellnb@gmail.com> - 2019-11-16 15:40 +0100
                Re: debcheckroot v2.0 released Patrick Schleizer <adrelanos@riseup.net> - 2019-11-19 13:40 +0100
                Re: debcheckroot v2.0 released Elmar Stellnberger <estellnb@gmail.com> - 2019-11-20 12:30 +0100
                Re: debcheckroot v2.0 released Patrick Schleizer <adrelanos@riseup.net> - 2019-11-25 12:40 +0100
                Re: debcheckroot v2.0 released Elmar Stellnberger <estellnb@gmail.com> - 2019-11-25 18:00 +0100
                Re: debcheckroot v2.0 released Elmar Stellnberger <estellnb@gmail.com> - 2019-12-10 17:40 +0100
                Re: debcheckroot v2.0 released Elmar Stellnberger <estellnb@gmail.com> - 2019-11-27 12:10 +0100
                Re: debcheckroot v2.0 released Cindy Sue Causey <butterflybytes@gmail.com> - 2020-01-17 14:40 +0100
                Re: debcheckroot v2.0 released Elmar Stellnberger <estellnb@gmail.com> - 2020-01-17 17:00 +0100
                Re: debcheckroot v2.0 released Elmar Stellnberger <estellnb@gmail.com> - 2020-01-17 17:20 +0100
                Re: debcheckroot v2.0 released Elmar Stellnberger <estellnb@gmail.com> - 2020-03-04 20:20 +0100
                Re: debcheckroot v2.0 released Elmar Stellnberger <estellnb@gmail.com> - 2020-03-04 20:50 +0100
                Re: debcheckroot v2.0 released Elmar Stellnberger <estellnb@gmail.com> - 2020-03-04 21:00 +0100
                Re: debcheckroot v2.0 released Elmar Stellnberger <estellnb@gmail.com> - 2020-03-04 21:00 +0100
                Re: debcheckroot v2.0 released Elmar Stellnberger <estellnb@gmail.com> - 2020-03-23 17:10 +0100
                Re: debcheckroot v2.0 released Paul Wise <pabs@debian.org> - 2020-03-24 04:40 +0100
                Re: debcheckroot v2.0 released Paul Wise <pabs@debian.org> - 2020-03-24 11:20 +0100
                Re: debcheckroot v2.0 released Elmar Stellnberger <estellnb@elstel.org> - 2020-03-24 15:50 +0100
                Re: debcheckroot v2.0 released Paul Wise <pabs@debian.org> - 2020-03-25 03:00 +0100
                Re: debcheckroot v2.0 released Elmar Stellnberger <estellnb@elstel.org> - 2020-03-25 11:30 +0100
                Re: debcheckroot v2.0 released Elmar Stellnberger <estellnb@elstel.org> - 2020-03-26 11:10 +0100
                Re: debcheckroot v2.0 released "vince@vheuser.com" <vince@vheuser.com> - 2020-04-01 20:10 +0200
                Re: debcheckroot v2.0 released Paul Wise <pabs@debian.org> - 2020-04-02 02:00 +0200
                Re: debcheckroot v2.0 released Lewis Yarema <lewisyarema91@gmail.com> - 2020-04-02 11:20 +0200
                Re: debcheckroot v2.0 released Elmar Stellnberger <estellnb@elstel.org> - 2020-04-02 17:00 +0200
                Re: debcheckroot v2.0 released Elmar Stellnberger <estellnb@elstel.org> - 2020-04-03 13:40 +0200
                Re: debcheckroot v2.0 released Elmar Stellnberger <estellnb@elstel.org> - 2020-04-02 16:50 +0200
                Re: debcheckroot v2.0 released Elmar Stellnberger <estellnb@elstel.org> - 2020-04-04 09:50 +0200
                Re: debcheckroot v2.0 released William Gagnebé <william.gagnebe@gmail.com> - 2020-04-05 12:20 +0200
                Re: debcheckroot v2.0 released l0f4r0@tuta.io - 2020-04-05 12:30 +0200
                Re: debcheckroot v2.0 released Elmar Stellnberger <estellnb@elstel.org> - 2020-04-07 17:50 +0200
                Re: debcheckroot v2.0 released "Niall O'Reilly" <Niall.oReilly+lists@no8.be> - 2020-04-02 18:30 +0200
                Re: debcheckroot v2.0 released Lee <ler762@gmail.com> - 2020-04-02 21:00 +0200
                Re: debcheckroot v2.0 released Elmar Stellnberger <estellnb@elstel.org> - 2020-04-02 21:40 +0200
                Re: debcheckroot v2.0 released Elmar Stellnberger <estellnb@elstel.org> - 2020-04-03 13:50 +0200
                Re: debcheckroot v2.0 released Lee <ler762@gmail.com> - 2020-04-04 00:50 +0200
                Re: debcheckroot v2.0 released Elmar Stellnberger <estellnb@elstel.org> - 2020-04-04 09:40 +0200
                Re: debcheckroot v2.0 released Bjørn Mork <bjorn@mork.no> - 2020-04-14 09:30 +0200
                arbitrary code execution on unformatted usb stick Elmar Stellnberger <estellnb@elstel.org> - 2020-04-25 15:40 +0200
                Re: arbitrary code execution on unformatted usb stick Elmar Stellnberger <estellnb@elstel.org> - 2020-04-25 15:50 +0200
                Re: arbitrary code execution on unformatted usb stick Elmar Stellnberger <estellnb@elstel.org> - 2020-05-02 17:00 +0200
                Re: arbitrary code execution on unformatted usb stick Elmar Stellnberger <estellnb@elstel.org> - 2020-05-02 17:10 +0200
                Fwd: Re: arbitrary code execution on unformatted usb stick estellnb@elstel.org - 2020-05-02 20:50 +0200
                Re: debcheckroot v2.0 released Elmar Stellnberger <estellnb@gmail.com> - 2020-03-21 17:40 +0100
      Probably a false alarm Re: Have I caught a firmware attack in the  act? Or am I just paranoid? "Rebecca N. Palmer" <rebecca_palmer@zoho.com> - 2019-08-24 18:50 +0200

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