Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 9d6f4a27df69e9bd…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-25 10:30:28 Authoring application: Microsoft Excel
MD5: 8ccbbf5bfb1ebadb45dac4309b6f8da4 SHA-1: c5745edbb70e4bcce3fc7a00485e0af99c1d5694 SHA-256: 9d6f4a27df69e9bddab42cc60add29ca12a21889c43b3de264ab7a4cbee331fe
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The file is an Excel 4.0 macro-enabled workbook containing an Auto_Open function, which is a common technique for executing malicious code upon opening. The critical heuristic firings indicate the presence of dangerous formula APIs within the XLM macro, suggesting it's designed to run arbitrary commands. No specific IOCs like URLs or hashes were extracted, but the Auto_Open macro itself is the primary indicator of malicious intent.

Heuristics 3

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
67239aad87ec0051435dbc25bb843e8907fcb1e8824e0f8e7e8c4944341129d1
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6479 bytes