Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 c8f3fd9ca3e32539…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:41:41 Authoring application: Microsoft Excel First seen: 2021-10-14
MD5: 599e90538dc495846df351788eca9fa3 SHA-1: 1d47e041e2f6276826e06764339b16e751e625e4 SHA-256: c8f3fd9ca3e325392feb7a4c250fde16ddda3f0072f18101804530a7c21151f3
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 sheet containing an Auto_Open defined name, which is a critical indicator of malicious intent. The presence of dangerous formula APIs like RUN suggests the macro is designed to execute arbitrary code. This pattern is commonly used to download and execute a second-stage payload, making it a high-risk artifact.

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) 6773 bytes
SHA-256: b87aea04883ed68c0996ed36bfdffb340750e7eb42b9e4b205637ef61ce89ed9
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     16 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  ZADaVeK
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!C150 
' 0018     23 LABEL : Cell Value, String Constant - bEaAyLql len=0 
' 0018     25 LABEL : Cell Value, String Constant - CEGJEeHAZQ len=0 
' 0018     27 LABEL : Cell Value, String Constant - hChdvpLtSjOF len=0 
' 0018     20 LABEL : Cell Value, String Constant - IMEGw len=0 
' 0018     24 LABEL : Cell Value, String Constant - kCkTOYLCF len=0 
' 0018     25 LABEL : Cell Value, String Constant - KhXMFhybbZ len=0 
' 0018     22 LABEL : Cell Value, String Constant - lGQRpIU len=0 
' 0018     26 LABEL : Cell Value, String Constant - LPYSFnggrYP len=0 
' 0018     23 LABEL : Cell Value, String Constant - LRwZvabG len=0 
' 0018     27 LABEL : Cell Value, String Constant - LxPRktrRelvf len=0 
' 0018     26 LABEL : Cell Value, String Constant - njOfHdpXALo len=0 
' 0018     22 LABEL : Cell Value, String Constant - pJrnOTw len=0 
' 0018     25 LABEL : Cell Value, String Constant - QXevYerpng len=0 
' 0018     21 LABEL : Cell Value, String Constant - SEHrfh len=0 
' 0018     23 LABEL : Cell Value, String Constant - SuBfhFfe len=0 
' 0018     20 LABEL : Cell Value, String Constant - THdlA len=0 
' 0018     25 LABEL : Cell Value, String Constant - TqVpAYZEYA len=0 
' 0018     21 LABEL : Cell Value, String Constant - VLuNAJ len=0 
' 0018     26 LABEL : Cell Value, String Constant - yCDzJPVIlEm len=0 
' 0018     25 LABEL : Cell Value, String Constant - YDkBvJAVXz 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
' 0
... (truncated)

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