Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 543c8673e247b614…

MALICIOUS

Office (OLE)

230.5 KB Created: 2020-07-14 13:16:14 Authoring application: Microsoft Excel
MD5: 8d52afbb25bddff327a3e19666230739 SHA-1: e42a275a15f094191d77db882c21e91e9c4a1292 SHA-256: 543c8673e247b61417c4cad394f06a0c706a36d447746c11c063cb379216b856
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic for Applications T1204.002 Malicious File

The sample is an Excel 4.0 macro sheet that uses an Auto_Open macro, a common technique for executing malicious code upon opening the workbook. The document body displays a fake protection message, instructing the user to 'Enable Editing' and 'Enable Content', which is a social engineering tactic to bypass security warnings and trick users into enabling the macro. The presence of dangerous formula APIs in the XLM macro further indicates malicious intent, likely to download and execute a second-stage payload.

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
5d49bb331a99dc14529975f2a9d24fba75b6bb57da1ef82f7fb8a3638acf8146
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 226169 bytes