Heap Flag

Created the Monday 18 March 2019. Updated 3 years, 10 months ago.

ProcessHeap is located at 0x18 in the PEB structure. This first heap contains a header with fields used to tell the kernel whether the heap was created within a debugger. The heap contains two fields which are affected by the presence of a debugger. These fields are Flags and ForceFlags.

The values of Flags and ForceFlags are normally set to HEAP_GROWABLE and 0, respectively.

On 64-bit Windows XP, and Windows Vista and higher, if a debugger is present, the Flags field is set to a combination of these flags:

  • HEAP_GROWABLE (2)
  • HEAP_TAIL_CHECKING_ENABLED (0x20)
  • HEAP_FREE_CHECKING_ENABLED (0x40)
  • HEAP_VALIDATE_PARAMETERS_ENABLED (0x40000000)

When a debugger is present, the ForceFlags field is set to a combination of these flags:

  • HEAP_TAIL_CHECKING_ENABLED (0x20)
  • HEAP_FREE_CHECKING_ENABLED (0x40)
  • HEAP_VALIDATE_PARAMETERS_ENABLED (0x40000000)

Technique Identifier

U0112

Technique Tag

heapflag


Code Snippets

Additional Resources

External Links

The resources provided below are associated links that will give you even more detailed information and research on current evasion technique. It is important to note that, while these resources may be helpful, it is important to exercise caution when following external links. As always, be careful when clicking on links from unknown sources, as they may lead to malicious content.

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