Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 f0b96f15a9dd9a01…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:41:45 Authoring application: Microsoft Excel
MD5: e4e394e0542c9586f9e84b822c4a4b07 SHA-1: 8221c257be926cf776d8ab2a78cfda73cf2048d0 SHA-256: f0b96f15a9dd9a01614a8c6657f7bb1c5b692232d1a5cab814fb883a93ab75e7
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 macros with an Auto_Open defined name, which is a common technique for executing malicious code upon opening the document. The macro sheet contains a reference to a dangerous formula API, suggesting it's designed to perform harmful actions. No specific IOCs like URLs or hashes were extracted, but the technique itself is highly suspicious.

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
6e4f6b8df9f4bed9014b51edffb62a58dba42b4a5efefe184712cff974f77e55
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6590 bytes