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

Static analysis result for SHA-256 b0a083d761308be8…

MALICIOUS

Office (OLE) / .DOC

201.5 KB Created: 2020-04-02 13:52:08 Authoring application: Microsoft Excel
MD5: 8e210ff92e84d61446b1e6896b2aac76 SHA-1: 854cb85fad979edf21f159ecb9414b88c7b34fcb SHA-256: b0a083d761308be80e3fbf93fe355fd169cf5a11fed86c4a569b9f7f2dd8cca5
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The file is an Excel 4.0 macro sheet containing an Auto_Open defined name, which is a critical finding indicating automatic execution upon opening. The critical heuristic 'OLE_XLM_DANGEROUS_FN' specifically flags the use of dangerous formula APIs, including the 'RUN' function, confirming the intent to execute arbitrary commands. This points to a macro-based attack pattern designed to run malicious code when the document is opened.

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
27b7a1b9dc459d159c22eb3b392cfec7f350ddc6984f8d639fcb310dd55ed82a
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 39932 bytes