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

Static analysis result for SHA-256 4bbd3513e1b413fd…

MALICIOUS

Office (OOXML) / .DOCM

39.6 KB Created: 2017-05-25 19:12:00 UTC Authoring application: Microsoft Macintosh Word 14.0000
MD5: f01f9f9f40eab5183b2d60d9db9aafe7 SHA-1: 2d4a9901587bd7545571b004c8bf78a769e8c111 SHA-256: 4bbd3513e1b413fd2cd1a1a4350b3371eb3233be7bc41c61a5d5a080dd4d8cb9
442 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.001 PowerShell T1059.003 Windows Command Shell T1140 Deobfuscate/Decode Files or Information T1204.002 Malicious File

The sample contains a VBA macro with an AutoOpen subroutine that is triggered upon opening the document. This macro utilizes WScript.Shell to execute a decoded payload, which is obfuscated within the document's 'Comments' property. The script reconstructs a base64 encoded string from the document properties, decodes it, and then writes it to a temporary executable file before running it. This indicates a downloader or dropper functionality. The ClamAV detection 'Doc.Malware.Valyria-6728957-0' further supports the malicious nature.

Heuristics 10

  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
  • 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.
  • ClamAV: Doc.Malware.Valyria-6728957-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Malware.Valyria-6728957-0
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • 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 vbaProject.bin — VBA macros present
  • 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.motobit.com
    • http://Motobit.cz
    • http://schemas.microsoft.com/office/word/2010/wordprocessingCanvas
    • http://schemas.microsoft.com/office/mac/office/2008/main
    • http://schemas.openxmlformats.org/markup-compatibility/2006
    • http://schemas.openxmlformats.org/officeDocument/2006/relationships
    • http://schemas.openxmlformats.org/officeDocument/2006/math
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawing
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawing
    • http://schemas.openxmlformats.org/wordprocessingml/2006/main
    • http://schemas.microsoft.com/office/word/2010/wordml
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroup
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInk
    • http://schemas.microsoft.com/office/word/2006/wordml
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShape

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
3fbc2ef94a618e17d5a6ba5af930717982f8239ff4eded5753681755be17f4ca
vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 2931 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 shell/COM execution token(s). Carved macro source contains an auto-exec entry point and execution/download terms.
vbaProject_00.bin
635a875e3ae07b99a521c0222d87b4cab342ce6b00fdce8cbae6e5f81dd4492f
vba-project OOXML VBA project: word/vbaProject.bin 15872 bytes
Detection
ClamAV: Doc.Malware.Valyria-6728957-0
Obfuscation or payload: likely
Carved artifact contains 1 shell/COM execution token(s). Carved macro source contains an auto-exec entry point and execution/download terms.