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

Static analysis result for SHA-256 9a3a5342f3622dae…

MALICIOUS

Office (OOXML) / .XLSM

26.7 KB
MD5: 670b4edd167d97efab37f9311c208e36 SHA-1: 01ac5eb5a0015f2e3f2571eb10a7e370ac94e044 SHA-256: 9a3a5342f3622dae4aad4c9a6a31af4051df10343e2031b482481ab63ea1a107
128 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.001 PowerShell T1204.002 Malicious File

The XLSM file contains VBA macros that leverage an ActiveX control to launch a decoded Excel4 macro. This technique is commonly used to download and execute additional malicious content. The presence of 'ActiveX event launches decoded Excel4 macro' and 'ExecuteExcel4Macro' heuristics strongly suggests this behavior. No specific family could be identified, and no external IOCs were extracted.

Heuristics 4

  • VBA ActiveX event launches decoded Excel4 macro critical OLE_VBA_ACTIVEX_XLM_STAGER
    VBA code attached to an ActiveX/UserForm event decodes strings from worksheet cells through a Mid/Asc/Chr character-shift loop and passes the recovered formula text to ExecuteExcel4Macro. This is a high-confidence macro stager that bridges VBA event activation into XLM formula execution rather than a specific Office parser CVE.
  • ActiveX control high OOXML_ACTIVEX
    Malformed OOXML local headers contain ActiveX controls — can execute code
  • VBA project inside OOXML medium OOXML_VBA
    Malformed OOXML local headers contain vbaProject.bin — VBA macros present
  • Malformed OOXML package with recoverable local headers low OOXML_MALFORMED_ZIP_LOCAL_HEADERS
    The OOXML ZIP central directory is invalid or missing, but local file headers expose a recoverable Office package. This can create parser divergence between tolerant Office/ZIP readers and scanners that rely only on the central directory.