Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 acc134fc0956cbf4…

MALICIOUS

Office (OLE)

35.5 KB Created: 2020-11-25 10:41:56 Authoring application: Microsoft Excel First seen: 2021-06-13
MD5: bac086730ab18772505177b4a705ed21 SHA-1: eec77d9dbcf79bb06a965ea94c8d6b995b04b26a SHA-256: acc134fc0956cbf4b6c790a20e6b91449847390c8547b81df81d24325576b780
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The file is an Excel 4.0 macro-enabled workbook containing an Auto_Open function. This function is designed to execute arbitrary code, indicated by the presence of dangerous formula APIs like RUN. The macro sheet likely serves as a loader for a second-stage payload, although the specific download URL or execution details are not directly extractable from the provided evidence. The obfuscated document body content further suggests an attempt to conceal malicious activity.

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 xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 6554 bytes
SHA-256: bc7b2b2b8149f4f0be948865eaace141aa70ca967de4c821bcc2aa96306cef25
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     18 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  bLFNzYUmM
' 0018     23 LABEL : Cell Value, String Constant - afbFjAXw len=0 
' 0018     20 LABEL : Cell Value, String Constant - anVFh len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B133 
' 0018     21 LABEL : Cell Value, String Constant - CnGXxe len=0 
' 0018     23 LABEL : Cell Value, String Constant - DfOVtmkH len=0 
' 0018     24 LABEL : Cell Value, String Constant - DxpjABAqi len=0 
' 0018     23 LABEL : Cell Value, String Constant - DyjTGqzC len=0 
' 0018     26 LABEL : Cell Value, String Constant - EdGDlpFwkZD len=0 
' 0018     27 LABEL : Cell Value, String Constant - EElwNREMtnkg len=0 
' 0018     25 LABEL : Cell Value, String Constant - EtVpGxaIuT len=0 
' 0018     20 LABEL : Cell Value, String Constant - IoVQo len=0 
' 0018     26 LABEL : Cell Value, String Constant - IRmZEIExOIG len=0 
' 0018     26 LABEL : Cell Value, String Constant - JCXzwaOkWMw len=0 
' 0018     25 LABEL : Cell Value, String Constant - JlRWhqyctP len=0 
' 0018     21 LABEL : Cell Value, String Constant - lPpQar len=0 
' 0018     25 LABEL : Cell Value, String Constant - NboOVHRRbn len=0 
' 0018     20 LABEL : Cell Value, String Constant - nqnVP len=0 
' 0018     21 LABEL : Cell Value, String Constant - ntBIyB len=0 
' 0018     24 LABEL : Cell Value, String Constant - rASbkkdUw len=0 
' 0018     21 LABEL : Cell Value, String Constant - Vggmpf len=0 
' 0018     27 LABEL : Cell Value, String Constant - VxPSvvkvBTGI len=0 
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd   
... (truncated)

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