Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 4bf58623f91ff9a1…

MALICIOUS

Office (OLE)

655.0 KB Created: 2018-07-26 00:26:51 Authoring application: Microsoft Excel
MD5: 3d67b0c7d220a241c6eb2ed5660ac458 SHA-1: fceed53a83a376274c92d26c870f7b4abd201f56 SHA-256: 4bf58623f91ff9a19c2893061a2a14660f61b2294f976a9d80ab6b3d023c9892
296 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File

The Excel file contains a Workbook_Open macro that is obfuscated and designed to execute a second-stage payload. The macro uses CreateObject to write a script to a file named '//klAutoClose.sct' and then executes it using mshta. This indicates a downloader or dropper functionality.

Heuristics 9

  • 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.
  • Reference to Windows Script Host high SC_STR_WSCRIPT
    Reference to Windows Script Host
  • Reference to mshta.exe high SC_STR_MSHTA
    Reference to mshta.exe
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject 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.
  • VBA macros detected medium OLE_VBA_MACROS
    Document contains VBA macro code
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
1ebd083c3b8d6c171806be2ab19fa92332604207f2a9febe3ea4fb6a9e61a1fa		 vba-macro oletools.olevba.extract_macros (decoded VBA source) 1106 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.