Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b66d4d4627ad582b…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:38:12 Authoring application: Microsoft Excel First seen: 2021-09-15
MD5: 1182be09b5ccf432b9247e3aabb45d59 SHA-1: 752a7ad0d325fdb12d4492219fa8aaa9aa5d0fe3 SHA-256: b66d4d4627ad582bda80dff28f64081fa9fe024bf6cd8f8330c0727f0aa89d30
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a critical finding. This indicates the macro sheet is designed to execute automatically upon opening the workbook. The presence of dangerous formula APIs like RUN suggests the macro is intended to execute arbitrary commands, likely to download and execute a secondary payload. No specific URLs or hashes were extracted, limiting further IOC identification.

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) 6576 bytes
SHA-256: 6c2445b8137d3c30abc3f159140d61c476cf6a0e5d966d7853d28101b6a0ea2b
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     12 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  phl
' 0018     25 LABEL : Cell Value, String Constant - aRUCeUDhlb len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!E145 
' 0018     26 LABEL : Cell Value, String Constant - axkgQFLVeSW len=0 
' 0018     25 LABEL : Cell Value, String Constant - deXDUDyXst len=0 
' 0018     22 LABEL : Cell Value, String Constant - DMQhdNm len=0 
' 0018     20 LABEL : Cell Value, String Constant - epMrM len=0 
' 0018     26 LABEL : Cell Value, String Constant - gJvVeYmehhN len=0 
' 0018     27 LABEL : Cell Value, String Constant - HDPrLsrBEvDd len=0 
' 0018     22 LABEL : Cell Value, String Constant - igTPOpe len=0 
' 0018     21 LABEL : Cell Value, String Constant - JDjUHT len=0 
' 0018     24 LABEL : Cell Value, String Constant - jfgfADUZC len=0 
' 0018     20 LABEL : Cell Value, String Constant - jiYpL len=0 
' 0018     25 LABEL : Cell Value, String Constant - lVTKymSJit len=0 
' 0018     26 LABEL : Cell Value, String Constant - OYDOVXTOVbX len=0 
' 0018     21 LABEL : Cell Value, String Constant - RezDDf len=0 
' 0018     27 LABEL : Cell Value, String Constant - RQrFtmqaydFC len=0 
' 0018     23 LABEL : Cell Value, String Constant - sulhROpa len=0 
' 0018     27 LABEL : Cell Value, String Constant - vaoEBjnxnBcf len=0 
' 0018     25 LABEL : Cell Value, String Constant - vZsTYgYRir len=0 
' 0018     27 LABEL : Cell Value, String Constant - WZXoVLNAOdlL len=0 
' 0018     23 LABEL : Cell Value, String Constant - YoqXQzsW 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
'
... (truncated)

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