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

Static analysis result for SHA-256 5dc178da12c1f8d3…

MALICIOUS

Office (OLE) / .XLS

103.0 KB Created: 2006-09-16 00:00:00 Authoring application: Microsoft Excel
MD5: 18ba7f2b283c56ded1df45e22da575f3 SHA-1: f3927069fefeca5eedd10fc1eecbc38e6b8f6665 SHA-256: 5dc178da12c1f8d3f3fe5f929a64fe6f5b36049ab0a1a83e1b23a2110a72d51a
222 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment T1105 Ingress Tool Transfer

The file contains Excel 4.0 macros, specifically an Auto_Open function, which is a critical finding. This macro is designed to execute dangerous API functions and reconstruct a URL from a cell array. The macro attempts to download a file from the reconstructed URL, http://agnipankhpan.in/wrzjpkrcgr/5555555555.png, which is then likely executed. The document body also contains the same URL and references 'Kernel32', 'exe', and 'DownloadDirectoryA', further indicating a payload download and execution attempt.

Heuristics 6

  • 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.
  • URL reconstructed from XLM cell array (1 URL) critical OLE_XLM_CELL_ARRAY_URL
    Excel 4.0 macro sheet stages its payload URL across the BIFF8 Shared String Table (one quoted-char SST entry concatenated with & at runtime) or across individual numeric cells (one ASCII charcode per cell). The reconstructed URL is invisible to literal-bytes URL extraction because it is never contiguous in the workbook stream. URLs were recovered by walking the BIFF8 record stream and decoding SST entries plus LABELSST/RK/NUMBER cells.
  • 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
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://agnipankhpan.in/wrzjpkrcgr/5555555555.png
    • http://agnipankhpan.in/wrzjpkrcgr/5555555555.png�

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt
fb73fc49ba9c271271983c838bc08a8f05062b002da3ef947ae2da8f435d7308
xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 2271 bytes