If you are looking for the latest xdelta patch files, you can find them here!

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Here's a list of the Windows updates that I will be talking about in this paper:

Title	Products	Classification	Last Updated	Version	Size
March, 2017 Preview of Monthly Quality Rollup for Windows 7 (KB4012218)	Windows 7	Updates	3/16/2017	n/a	93.4 MB
March, 2017 Preview of Monthly Quality Rollup for Windows 7 for x64-based Systems (KB4012218)	Windows 7	Updates	3/16/2017	n/a	153.9 MB
March, 2017 Preview of Monthly Quality Rollup for Windows Server 2008 R2 x64 Edition (KB4012218)	Windows Server 2008 R2	Updates	3/16/2017	n/a	153.9 MB
March, 2017 Preview of Monthly Quality Rollup for Windows 8.1 (KB4012219)	Windows 8.1	Updates	3/16/2017	n/a	121.2 MB
March, 2017 Preview of Monthly Quality Rollup for Windows 8.1 for x64-based Systems (KB4012219)	Windows 8.1	Updates	3/16/2017	n/a	218.0 MB
March, 2017 Preview of Monthly Quality Rollup for Windows Server 2012 R2 (KB4012219)	Windows Server 2012 R2	Updates	3/16/2017	n/a	218.0 MB

About

After reading this article on gHacks, I was inspired to look into these new rollup updates that Microsoft released on March 16. Among other things included in these updates, the changelog mentions the following:

Enabled detection of processor generation and hardware support when PC tries to scan or download updates through Windows Update.

Which is just Microsoft's nice way of telling everyone who'd rather keep using Windows 7 or 8.1 on their Intel Kaby Lake or AMD Ryzen systems to fuck themselves. There have even been people with Intel and AMD systems from 2015 who have reportedly been locked out of Windows Update because of this!

Bad Microsoft!

Well then, time figure out how to fix this garbage.

I started by downloading the .msu package for my system (in my case, it was windows6.1-kb4012218-x64_590943c04550a47c1ed02d3a040d325456f03663.msu)

I extracted it using the command line expand tool, like this:

md "windows6.1-kb4012218-x64"
expand -f:* ".\windows6.1-kb4012218-x64_590943c04550a47c1ed02d3a040d325456f03663.msu" ".\windows6.1-kb4012218-x64"
cd ".\windows6.1-kb4012218-x64"
md "Windows6.1-KB4012218-x64"
expand -f:* ".\Windows6.1-KB4012218-x64.cab" ".\Windows6.1-KB4012218-x64"

Great, now there's thousands of .exe and .dll files to sort through! Just kidding. Sort of. Maybe. 🤔

I ended up using PowerShell to sort through all the binaries, like so:

Get-ChildItem -Filter "wu*" -Exclude "*.mui" -Recurse | ForEach-Object { $_.FullName }

That's narrowed it down quite a bit! This is now what we're looking at:

• wu.upgrade.ps.dll
• wuapi.dll
• wudriver.dll
• wups.dll
• wuapp.exe
• wuwebv.dll
• wuauclt.exe
• wuaueng.dll
• wups2.dll
• wucltux.dll
• wuapi.dll
• wudriver.dll
• wups.dll
• wuapp.exe
• wuwebv.dll

Next, I started comparing these binaries with the ones already on my system with BinDiff and Diaphora, starting with wuauclt.exe. After turning up empty with that (the two binaries were nearly identical), I decided to take a look at wuaueng.dll, which turned up quite a few interesting new functions:

EA	Name	Basicblock	Instructions	Edges
00000600001DCB9C	CWUTelemetryDownloadCanceledEvent::FireAsimovEvent(void)	36	446	53
00000600001D8F98	CWUTelemetryDownloadCanceledEvent::`scalar deleting destructor'(uint)	3	15	3
00000600001D8FD0	CWUTelemetryDownloadEvent::CWUTelemetryDownloadEvent(void)	1	58	0
00000600001DAEDC	CWUTelemetryDownloadEvent::Init(CReporter *,long,long,ushort const *,long,_GUID,_GUID,CReportingOptionalValues &,AsimovDataInAddition *)	6	50	8
00000600001DAFB8	CWUTelemetryDownloadEvent::InitializeMemebersFromOptionalData(tagOptionalData *)	27	91	40
00000600001D9100	CWUTelemetryDownloadEvent::~CWUTelemetryDownloadEvent(void)	2	60	1
00000600001DC2C4	CWUTelemetryDownloadFailedEvent::FireAsimovEvent(void)	36	446	53
00000600001DB114	CWUTelemetryDownloadStartedEvent::FireAsimovEvent(void)	36	446	53
00000600001DB9EC	CWUTelemetryDownloadSucceededEvent::FireAsimovEvent(void)	36	446	53
00000600001D8C48	CWUTelemetryEventFactory::FireTelemetryEvent(CReporter *,long,long,ushort const *,long,_GUID,_GUID,CReportingOptionalValues &,AsimovDataInAddition *)	11	76	17
00000600001D8574	CWUTelemetryEventFactory::GetTelemetryEvent(CReporter *,long,long,ushort const *,long,_GUID,_GUID,CReportingOptionalValues &,AsimovDataInAddition *,CWUTelemetryEvent * *)	77	395	127
00000600001DEE7C	CWUTelemetryInstallCanceledEvent::FireAsimovEvent(void)	34	409	50
00000600001D8DD4	CWUTelemetryInstallEvent::CWUTelemetryInstallEvent(void)	1	57	0
00000600001DD474	CWUTelemetryInstallEvent::Init(CReporter *,long,long,ushort const *,long,_GUID,_GUID,CReportingOptionalValues &,AsimovDataInAddition *)	6	50	8
00000600001DD550	CWUTelemetryInstallEvent::InitializeMemebersFromOptionalData(tagOptionalData *)	23	81	34
00000600001D8EFC	CWUTelemetryInstallEvent::~CWUTelemetryInstallEvent(void)	2	66	1
00000600001DE67C	CWUTelemetryInstallFailedEvent::FireAsimovEvent(void)	34	409	50
00000600001DF67C	CWUTelemetryInstallRebootPendingEvent::FireAsimovEvent(void)	34	409	50
00000600001D8D9C	CWUTelemetryInstallRebootPendingEvent::`scalar deleting destructor'(uint)	3	15	3
00000600001DD67C	CWUTelemetryInstallStartedEvent::FireAsimovEvent(void)	34	409	50
00000600001DDE7C	CWUTelemetryInstallSucceededEvent::FireAsimovEvent(void)	34	409	50
00000600001CAE68	CWUTelemetryScanFailedEvent::FireAsimovEvent(void)	31	416	46
00000600001CA100	CWUTelemetryScanRetryEvent::FireAsimovEvent(void)	9	108	13
00000600001CA588	CWUTelemetryScanSucceededEvent::FireAsimovEvent(void)	47	459	73
00000600001CB790	CWUTelemetryUnsupportedSystemClickSupportEvent::FireAsimovEvent(void)	5	22	7
00000600001CB9B0	CWUTelemetryUnsupportedSystemClickSupportEvent::`scalar deleting destructor'(uint)	3	17	3
00000600001CB7FC	CWUTelemetryUnsupportedSystemDetectionEvent::FireAsimovEvent(void)	5	22	7
00000600001CB970	CWUTelemetryUnsupportedSystemDetectionEvent::`scalar deleting destructor'(uint)	3	17	3
00000600001CB724	CWUTelemetryUnsupportedSystemNotificationDismissEvent::FireAsimovEvent(void)	5	22	7
00000600001CB9F0	CWUTelemetryUnsupportedSystemNotificationDismissEvent::`scalar deleting destructor'(uint)	3	17	3
00000600001CB6B8	CWUTelemetryUnsupportedSystemNotificationShowEvent::FireAsimovEvent(void)	5	22	7
00000600001CBA30	CWUTelemetryUnsupportedSystemNotificationShowEvent::`scalar deleting destructor'(uint)	3	17	3
0000060000102F08	IsCPUSupported(void)	20	157	31
00000600000AF3C0	IsDeviceServiceable(void)	7	31	8
00000600000832CC	TraceLoggingEnableForTelemetry(_TlgProvider_t const *)	16	86	23
0000060000083210	TraceLoggingSetInformation(_TlgProvider_t const *,_EVENT_INFO_CLASS,void *,ulong)	6	50	8

We have found culprits, IsDeviceServiceable(void) and IsCPUSupported(void)!

Solutions

IsCPUSupported(void) is only ever called by IsDeviceServiceable(void), which is called by five other functions. Luckily, there are a couple easy ways to kill this CPU check.

1. Patch wuaueng.dll and change dword_600002EE948 (see this line) which is at file offset 0x26C948, from 0x01 to 0x00. This makes IsDeviceServiceable(void) jump over its entire body and return 1 (supported CPU) immediately. This is my preferred method. Note: these offsets are only for the Windows 7 x64 version.

2. Patch wuaueng.dll and nop out all the instructions highlighted here in IsDeviceServiceable(void), this will enable the usage of the ForceUnsupportedCPU of type REG_DWORD under the registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Test\Scan (you will most likely have to create this registry key). Set this value to 0x00000001 to force unsupported CPUs, and back to 0x00000000 to change the behaviour back to default. You will probably need to restart your PC or restart the wuauserv service in order for changes to apply. This behaviour is undocumented and could be removed in future updates.

Caveats

The only downside of these solutions is you have to apply a new patch whenever wuaueng.dll gets updated.