Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 89d9dcfaf2a84a0c…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:39:48 Authoring application: Microsoft Excel
MD5: a8dc4d27425b6112f42ec1ddcc48eb06 SHA-1: 90c4f621dbbb9a693876013bce7bce09019f4623 SHA-256: 89d9dcfaf2a84a0c07ae64c0c6cc6654bddfdfed0a1f2db63004d7373308b8af
140 Risk Score

Malware Insights

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

The critical heuristics indicate the presence of Excel 4.0 (XLM) macros, specifically an Auto_Open defined name, which is a common technique for executing malicious code. The `RUN=0` in the `risky-formula=2` heuristic suggests the macro likely calls a function to execute arbitrary code, rather than just displaying a message box. The macro sheet itself contains obfuscated data, further suggesting 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
9b182150cf8b022050d0012d94d3cc869e9b8cfd6ee4acad9d0b60446303283b
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6712 bytes