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

Static analysis result for SHA-256 408a7bd4b45c7734…

MALICIOUS

Office (OLE) / .XLSX

138.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel First seen: 2022-07-13
MD5: a2a66e11f40a9051bff6a9c69bd843cc SHA-1: c7a3040910cabe2db049e6548358fae3fa27f6c3 SHA-256: 408a7bd4b45c7734ba5fe8429d12b60b832f0bb360ed5988d8e9885b84d7824b
160 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a critical finding. The presence of a 'Macro/content-enable lure' heuristic indicates the document attempts to trick the user into enabling macros. The macro sheet contains a reference to a URL, 'http://ipok12bcame03shzpiq.xyz/i.', and a local file path '../zfbfg.ere', suggesting the macro's purpose is to download and execute a second-stage payload. The use of XLM macros and a lure to enable them points to a downloader or initial access stage.

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
3a08691eed72e5ed205a0b2d682f61d57bf1de10bae67e5c55da30ecdcba1b08
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 4335 bytes