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Re-sauce, Part 3

November 27, 2020 in Archaeology, Clustering, Code Injection, File Formats ZOO, Forensic Analysis

I like extracting data from many samples because this way I often discover new things. Combing through a set of manifest files I have extracted from a large sampleset of good samples was an interesting exercise and brought a few interesting findings.

Manifest files I came across were saved as plain text, Unicode 16 LE, and utf8. Some were malformed, some used incorrect data, others included commented out manifest sections and sometimes the commented out parts would use HTML entities to represent opening and closing brackets. Quotation marks vs. apostrophes, boilerplate values (e.g. name = “CompanyName.ProductName.YourApplication”, name = “YourCompanyName.YourDivision.YourApp”, etc.), and typos (e.g. “schema-microsoft-com:asm.v3”, or “urn:schemas-microsoft.com:asm.v3”).

I tried to see if I can find any publicKeyToken outliers — these are often used to reference a specific library version – the most popular being comctl32.dll v6.0 enabling visual styles back in the days when it still mattered (publicKeyToken=”6595b64144ccf1df”).

Quick histogram of publicKeyToken values shows a small number of unique values, some of which are kinda questionable (e.g. empty, zeroed, or using a reference):

publicKeyToken="6595b64144ccf1df"
publicKeyToken="1fc8b3b9a1e18e3b"
publicKeyToken="000000000000000"
publicKeyToken="02ad33b422233ae3"
publicKeyToken="73A0BB510A53FB51"
publicKeyToken="31BF3856AD364E35"
publicKeyToken="0000000000000000"
publicKeyToken="dfbe2673baf698eb"
publicKeyToken="6595B64144CCF1DF"
publicKeyToken="89845dcd8080cc91"
publicKeyToken="13acf979d16e8a17"
publicKeyToken="b03f5f7f11d50a3a"
publicKeyToken="B03F5F7F11D50A3A"
publicKeyToken="$(Build.WindowsPublicKeyToken)"
publicKeyToken="5a496c7842cd4787"
publicKeyToken="296da4bedbebef8f"
publicKeyToken="df38d5d136a3092e"
publicKeyToken=""
publicKeyToken="fcc99ee6193ebbca"
publicKeyToken="b77a5c561934e089"
publicKeyToken="81e233547d425e6b"
publicKeyToken="6bd6b9abf345378f"
publicKeyToken="C7153A0601FA8C89"
publicKeyToken="7a259a25b8d448e5"
publicKeyToken="654bb64156ccf1af"
publicKeyToken="40C4B6FC221F4138"
publicKeyToken="31bf3856ad364e35"
publicKeyToken="1fc8b3b9a1e18e3c"
publicKeyToken="02d1dcd786c7c243"
publicKeyToken="f92d94485545da78"
publicKeyToken="a03853097df2bf0c"
publicKeyToken="A2625990D5DC0167"
publicKeyToken="71E9BCE111E9429C"
publicKeyToken="669E0DDF0BB1AA2A"
publicKeyToken="5120E14C03D0593C"
publicKeyToken="47D0C84D0EBB13E5"
publicKeyToken="4267b751a96a28a1"
publicKeyToken="30AD4FE6B2A6AEED"

Another statistic I was interested in was requestedExecutionLevel, but it didn’t bring anything interesting:

level="asInvoker"
level="highestAvailable"
level="leastPrivilege"
level="requireAdministrator"

Looking at processorArchitecture we get:

$(build.processorArchitecture)
*
AMD64
Amd64
IA64
MSIL
SXS_PROCESSOR_ARCHITECTURE
X64
X86
amd64
arm
ia64
msil
x64
x86

For uiAccess:

"false"
FALSE
False
TRUE
True
false
true
true|false

Another target of these analysis were URIs. These constantly pop up during memdump analysis and knowing a list of clean ones can save us some time. Here’s a list I extracted (including these prefixed with ‘urn’):

http://blogs.msdn.com/b/chuckw/archive/2013/09/10/manifest-madness.aspx
http://ipmsg.org/tools/fastcopy.html
http://ltsc.ieee.org/xsd/LOM
http://manifests.microsoft.com/win/2004/08/windows/events
http://mozilla.org/MPL/2.0/.
http://msdn.microsoft.com/en-us/library/aa374191
http://msdn.microsoft.com/en-us/library/aa374191(VS.85).aspx
http://msdn.microsoft.com/en-us/library/aa965884%28v=vs.85%29.aspx
http://msdn.microsoft.com/en-us/library/dd371711
http://msdn.microsoft.com/en-us/library/hh848036
http://msdn.microsoft.com/en-us/library/hh848036(v=vs.85).aspx
http://msdn.microsoft.com/en-us/library/ms633543.aspx
http://msdn.microsoft.com/en-us/library/windows/desktop/dn302074%28v=vs.85%29.aspx
http://msdn.microsoft.com/windowsvista/prodinfo/what/security/default.aspx?pull=/library/en-us/dnlong/html/AccProtVista.asp
http://opensource.org/licenses/cpl.php
http://opensource.org/licenses/cpl1.0.php
http://schemas.microsoft.com/SMI/2005/WindowsSettings
http://schemas.microsoft.com/SMI/2010/WindowsSettings
http://schemas.microsoft.com/SMI/2011/WindowsSettings
http://schemas.microsoft.com/SMI/2016/WindowsSettings
http://schemas.microsoft.com/SMI/2017/WindowsSettings
http://schemas.microsoft.com/win/2004/08/events
http://social.msdn.microsoft.com/Forums/en/winformssetup/thread/7787c8b9-18c3-4135-bd8a-2802eba98e3c
http://www.adlnet.org/xsd/adlcp_v1p3
http://www.apache.org/licenses/LICENSE-2.0
http://www.imsglobal.org/xsd/imscp_v1p1
http://www.w3.org/2000/09/xmldsig#
http://www.w3.org/2000/09/xmldsig#sha1
http://www.w3.org/2001/XMLSchema
http://www.w3.org/2001/XMLSchema-instance
http://yourserver/iis_auth.asp?debug=1
urn:0073chemas-microsoft-com:asm.v3
urn:schemas-microsoft-com:asm.v1
urn:schemas-microsoft-com:asm.v2
urn:schemas-microsoft-com:asm.v3
urn:schemas-microsoft-com:clickonce.v1
urn:schemas-microsoft-com:clickonce.v2
urn:schemas-microsoft-com:compatability.v1
urn:schemas-microsoft-com:HashTransforms.Identity
urn:schemas-microsoft-com:HashTransforms.ManifestInvariant

Finally, attributes (note, some may only exist within comments, that is, between <!–…-> not the actual manifest XML):

name
iid
version
clsid
progid
hash
description
proxyStubClsid32
tlbid
Id
numMethods
publicKeyToken
task
message
language
value
xmlns
processorArchitecture
uiAccess
level
type
class
file
standalone
inType
encoding
mask
flags
manifestVersion
threadingModel
keywords
size
chid
runtimeVersion
guid
xmlns:asmv3
company
optional
outType
helpdir
xmlns:co.v2
copyright
allowDelayedBinding
opcode
xmlns:asmv2
length
xmlns:ms_asmv3
buildType
hashalg
parameters
xmlns:adlcp
xsi:schemaLocation
xmlns:cmp
culture
xmlns:ms_asmv1
profile
xmlns:ms_windowsSettings
xmlns:xsi
baseInterface
majorVersion
face
xmlns:xsd
miscStatusContent
resourceFileName
xmlns:asmv1
isolation
dependencyType
servicePackMajor
xmlns:co.v1
channel
xmlns:lom
assemblyname
xmlns:ms_asmv2
messageFileName
xmlns:ms_compatibility
template
xmlns:mssv2
minorVersion
miscStatus
enabled
asmv2:product
product

And last, but not least… this classic paper [PDF warning] from 2006 on manifest file abuse was yet another reason I looked at manifest files en masse. I speculated that maybe, maybe, maybe, maybe there are some signed executables that take advantage of manifest’ file tag as described in the document:

and inadvertently may become a vehicle for a ‘by design’ manifest-based DLL side-loading. The scenario would play like this: you run a signed executable that uses a manifest leveraging the file tag and you provide it the malicious DLL named as the manifest expects and place it in a current directory. Should work?

After grepping the manifest files for <file tag I found quite a few of them. So many that I can’t paste it here. But you can view them here.

What’s next? Obviously, more research.

Re-sauce, Part 2

November 18, 2020 in Archaeology, Clustering, File Formats ZOO, Forensic Analysis

In the part 1 I covered the most frequently used resource names. Today I will cover an obscure type of resources instead. Some developers like to use strings to name the resources and use them instead of numerical IDs. Many of these are prefixed with the ‘IDD_’, so it makes for an easy target.

Grepping through a large collections of exported resources one can find the following ‘custom-named’ resource names (see file).

Browsing through the content one can find a number of IDDs that are clearly very old e.g.

  • IDD_WIZ97SHEET
  • IDD_DISKETTE
  • IDD_INSERT_DISK

but also lots of very boring names e.g.

  • IDD_DIALOG1
  • IDD_DIALOG2
  • IDD_DIALOG3
  • IDD_DIALOG4
  • IDD_ABOUTBOX
  • IDD_DIALOG_FONT
  • IDD_FONT
  • IDD_UNUSED1
  • etc.

— most likely names auto-created by RAD resource editors. There are some funny typos e.g. IDD_SPLAHSCREEN. Finally, there same some more enigmatic and interesting names like

  • IDD_DEBUG*
  • IDD_NTOPEN
  • IDD_NTCLOSE
  • IDD_CREDITCARD

but these are not really research-worthy.

How can you use this list?

Apart from being an archaeological curiosity this may actually be quite helpful to know which IDD_ resources are at least known in a ‘good sampleset’ space. With that you could create yara rules, and perhaps more advanced ‘good file’ detections. And if you write a PE Viewer/editor/parser, you could always highlight these as ‘known good resources’.

Overall, curiosity more than anything useful, but that’s one of the reasons why we are digging it… out.