Malicious Office (OLE) / .XLS — malware analysis report

Static analysis result for SHA-256 715c57b278b2aaae…

MALICIOUS

Office (OLE) / .XLS

31.0 KB Created: 2021-01-25 13:50:02 Authoring application: Microsoft Excel
MD5: 570413ea3e81f3b3c8788d756c851d25 SHA-1: 653ff5446802d6e3520f4032c7cd7997a4671f89 SHA-256: 715c57b278b2aaae252f23f693985277b520865af3b328eef80506875a456cdc
160 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.005 Visual Basic T1203 Exploitation for Client Execution

The sample is an Excel 4.0 (XLM) macro-enabled spreadsheet. It contains an Auto_Open macro that uses dangerous functions, indicating it's designed to execute malicious code. The document body explicitly instructs the user to 'Enable Editing' and 'Enable Content', a common social engineering tactic to bypass macro security. No specific family could be identified, but the techniques used are consistent with macro-based malware droppers.

Heuristics 4

  • 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.
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
8a99905b6f27fa9bebce98932689ba39660f48944384c536b672736041830fdd
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 3311 bytes