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

Static analysis result for SHA-256 5a3cf4d6cd1b7747…

MALICIOUS

Office (OLE) / .XLS

42.0 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: e9557f19e97cad88a8d149c9029e8ac9 SHA-1: 7d7cfe00992caf0bbd82806240200d2b3faf6995 SHA-256: 5a3cf4d6cd1b77479033b9b275e3884098651ea28c969f412fb3be0ea4daf57e
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a critical finding indicating automatic execution upon opening. The presence of dangerous formula APIs like RUN suggests the macro is designed to execute external commands or download payloads. While no specific URLs or hashes were extracted, the technique strongly implies a downloader or initial execution stage for further malicious activity.

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
b0626311b40e1e72fe0bc5e8d39826d9635ddea48eafb0478f05fa0951c88a26
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 8216 bytes