47
votes
Accepted
Does rebooting a phone daily increase your phone's security?
Rebooting a phone regularly helps cleaning non-persistent malware, i.e., malware that only exist in memory – and non-persistent malware alone, as explained in Paul Ducklin's Sophos blog article on the ...
- 19.4k
11
votes
Accepted
Write-protection at hardware level for security
Quis custodiet ipsos custodes?
Before I begin, I'd like to explain a bit about the term trust as it is used in an information security context. In infosec, trust often has the opposite meaning of what ...
- 67.3k
9
votes
What's stopping someone from copying my HDD/SSD?
Physical access is usually a huge security issue, depending also on your threat model or, in other words, what the attacker is willing to do with your machine.
Full disk encryption is a great security ...
- 15.9k
5
votes
Accepted
Is Secure Boot really Secure?
systemd-boot has to be signed as well. The original signed gummiboot respects the 'secure' boot process and requires that the binaries it is to launch are signed as well:
https://www.rodsbooks.com/efi-...
- 2,780
5
votes
How are TPMs provisioned for Intel Trusted Execution Environment (TXT)?
The Intel TXT is a complex system designed to provide a hardware layer of security that can prevent software layer changes from resulting in increased access for attackers. Through use of stored ...
- 1,451
5
votes
Accepted
Why are pins required on boot on devices with fingerprint readers?
The PIN is used to derive an encryption key, whereas the fingerprint is used only for authentication. Because the encryption key is kept in memory during runtime, it is lost after a reboot and needs ...
- 67.3k
4
votes
Accepted
Will converting a MBR disk to GPT, formatting and the converting back to MBR remove a infected boot record.
No, not unless the infection exclusively resides on the MBR. It can easily exist on the bootloader or any other stage in the boot process. Also note that GPT has two backup MBRs on it, though they are ...
- 67.3k
4
votes
Accepted
Can dual-boot, encrypted Windows 7 installations be fairly well secured against each other?
It depends on your threat model. There is one problem I can see: disk encryption does not guarantee integrity. That means the other operating system installation could change the data on the first one....
- 7,858
4
votes
Accepted
Can a Windows program compromise the desktop hardware without giving administrator rights?
If I run a program on a Windows 10 machine, can the program install a virus on an attached USB drive
Yes. You don't need admin access to write to a USB drive.
can it install a virus into the ...
- 11k
4
votes
What's stopping someone from copying my HDD/SSD?
Time.
Yes, someone could clone your entire hard drive, but this usually takes a long time. An attacker would have to open your computer's case, remove the drive, plug it into a dock, clone its ...
- 239
4
votes
Accepted
Understanding FDE: Is the encrypted Linux protected against a compromised boot volume?
Full-disk encryption protects against theft. That is, it protects against a scenario where an attacker gains access to the device, and the owner loses access to the device at that point.
Full-disk ...
3
votes
Full disk encryption on dual boot system (Truecrypt/Veracrypt)
In an ideal world, I would like to introduce a third boot loader, loaded before Grub, that handles the decryption of the system partitions
As this would be a nice solution, the problem is that a ...
- 606
3
votes
Is Secure Boot really Secure?
I think the theory is that each level only signs an instance of the next level if it implements signature checks correctly.
In other words systemd-boot is supposed to do signature checks, and only ...
- 2,004
3
votes
Would it add security to set a GRUB password if HDDs are encrypted and UEFI settings can be opened anyway?
Adding grub password is needed to protect the boot sequence, but protecting the boot sequence only makes sense if you protect the entire boot sequence, in other words if you enable grub password, you ...
- 31.6k
3
votes
Accepted
System encryption on a uefi system?
The key here is privacy vs integrity.
If your data volume (/home, /var/log and anything else with sensitive data) is encrypted then you're primarily just assuring privacy, whereas for /boot you want ...
- 587
3
votes
Android verified boot within the boot sequence
AVB is enforced by the bootloader and dm-verity is enforced by the kernel. Both run consecutively in android boot flow.
In factory:
OEM constructs hashtree of /system, /vendor, product and ODM ...
- 6,971
3
votes
Accepted
VeraCrypt - Windows boots Automated Repair on UEFI/GPT
OK, I came up with a solution and it works even after I switch off the computer. In BOOTICE I modified the Windows Boot Manager to load "\EFI\VERACRYPT\DCSBOOT.EFI" (the VeraCrypt loader) instead of ...
- 81
3
votes
How is hibernation supported, on machines with UEFI Secure Boot?
Vulnerable But Addressable
As user2213 indicated, hibernation file attacks are not prevented by anything in the UEFI Secure Boot specification.
The solution is to use full-disk encryption on the ...
- 3,970
3
votes
Accepted
Understanding Secure Boot
However, what ensures that CPU really starts booting the system from the correct ROM?
Usually ROM are sorted onto motherboard. Since information once written to ROM can not be electronically altered, ...
- 573
3
votes
What's stopping someone from copying my HDD/SSD?
Yes, it is possible to clone drives using some external connector (SSD/HDD usb connectors/Tableau Hardware) and software (osf/winhex). Cloning can be done in both states. It takes 30 - 40 min depends ...
- 31
3
votes
What's stopping someone from copying my HDD/SSD?
Physical Security
An often overlooked part of Information Security. Lock the PC down by disabling external ports (USB, Serial, etc), and physically secure the PC so they cant take it or open it. ...
2
votes
How Do Rootkits & Other Low-Level Malware Still Manage to Load on Systems Protected by Secure Boot (and TB/MB)?
Much of the computer security enhancements are there to make it difficult for general attackers to gain access to computers while still allowing western governments to crack in to them easily. So a ...
- 392
2
votes
UEFI Firmware integrity measurement
Intel Security research team recently released a tool dedicated to this kind of UEFI sanity checking:
CHIPSEC UEFI integrity scanner
→ chipsec / github
You will need a secure reference whitelist to ...
- 3,078
2
votes
UEFI Firmware integrity measurement
In most cases the UEFI sits in a non-volatile memory (e.g. Nand memory embedded into the mother-board) , a good approach for such protection against FW compromise may be :
BEFORE first writing of the ...
- 129
2
votes
Accepted
Does periodically rebooting secure-boot-enabled devices improve security by preventing persistent compromise?
Periodic rebooting does very little to improve device security in general.
Secure boot is designed to protect your system from attacks that target the boot process, e.g. the part of a computer's ...
- 9,293
2
votes
Accepted
Exploiting a Linux startup script that is world writable
Arrange, to run as root:
cp $(which bash) $(which bash).muhaha
chmod u+s $(which bash).muhaha
Now, executing $(which bash).muhaha -p gives root to any user. You can even run a script as root with $(...
- 1,230
2
votes
Verifying that the CRTM is read-only for the purpose of trusted computing
As the name implies, a CRTM is the Core Root of Trust for Measurement. By definition, a Root of Trust of a given system is trusted because its correct operation cannot be verified by that system. In ...
- 66
2
votes
Can dual-boot, encrypted Windows 7 installations be fairly well secured against each other?
The short answer is that it's not secure.
Not only aren't dual-boot installations secure against each other, they're actually less secure when the other install is running. Normally Windows tries to ...
- 2,780
2
votes
Accepted
Can malware migrate between OSes on the same machine?
They are not correct. Anything left in memory after the machine reboots, even if not overwritten, won't be active. This is because there is no code in any used operating system which looks in ...
- 67.3k
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