Malicious Office (OOXML) / .XLSM — malware analysis report

Static analysis result for SHA-256 3dcc673a854935ef…

MALICIOUS

Office (OOXML) / .XLSM

598.0 KB Created: 2006-09-16 00:00:00 UTC Authoring application: Microsoft Excel 16.0300 First seen: 2025-12-23
MD5: 459a8eb5c77c6a257e9349246b18c664 SHA-1: 581edcc35bb6751719b9f2a497021800885c0204 SHA-256: 3dcc673a854935ef98a19331d51622000a866396a430f81014795b9dca996a04
418 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.003 Windows Command Shell T1204.002 Malicious File T1087.001 Local Accounts T1059.001 PowerShell

The sample is a macro-enabled Excel file (XLSM) that contains a Workbook_Open macro, indicating automatic execution upon opening. Critical heuristics indicate the use of Shell() calls and WMI to create processes, along with obfuscated auto-exec loaders. This suggests the VBA code is designed to download and execute a second-stage payload. The embedded URLs, while currently flagged as benign, are part of the document's content and could be used for staging.

Heuristics 12

  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • VBA WMI Win32_Process launcher critical OLE_VBA_WMI_PROCESS_CREATE
    VBA macro builds or references a WMI moniker for Win32_Process and invokes .Create to start a command. This is a high-confidence macro execution chain that often hides the WMI class name through string concatenation or helper functions.
  • 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.
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call
  • 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 high 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.
  • VBA project inside OOXML medium OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
  • Hidden worksheet (veryHidden) low OOXML_HIDDEN_SHEET
    Excel workbook contains 2 hidden sheet(s) — hidden sheets are commonly used to conceal macro code, staging data, or intermediate payload construction
  • 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://www.oracle.com/bne
    • http://support.microsoft.com/kb/161930

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
81360b04f8245e45e4e572bfc5202a3f84c667befccd2072da99513e4be4b3ec		 vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 399152 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).
vbaProject_00.bin
b38eda031676d2b3842acbe096c72cc058357cd28b66e530148669e134363045		 vba-project OOXML VBA project: xl/vbaProject.bin 954880 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 eval/decoder/string-building token(s).

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