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

Static analysis result for SHA-256 cee92b32dd31b030…

MALICIOUS

Office (OLE) / .XLS

230.0 KB Created: 2020-09-20 21:17:44
MD5: 6867cb005aff8668936e16af6eee7f5d SHA-1: a402fea3d669b84e679f8c443ba3d50bfc0d7551 SHA-256: cee92b32dd31b030d24cd7cb32b62c9700967d620537ce64a38eca3814941f5c
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 PowerShell T1059.001 PowerShell T1204.002 Malicious File

The sample contains Excel 4.0 macros with an Auto_Open entry, which is a critical finding. The macros construct and execute PowerShell commands. One command downloads a file named 'pd.bat' from 'https://cutt.ly/kjWPyul' to the temporary directory, and subsequent commands execute this batch file. This indicates the macro is acting as a downloader for 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
a8f1191b6e7ee424e42f36fed2ea1a08034422ee3f51dbb214958a47b1786933
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 1550 bytes