Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 82d638ddae3c1bd7…

MALICIOUS

Office (OLE)

35.5 KB Created: 2020-11-27 11:47:46 Authoring application: Microsoft Excel First seen: 2021-06-13
MD5: c99710e462fba0706e5600afec535d38 SHA-1: 3d67c4c5245c0b5790cd00318a1813a4d3533d89 SHA-256: 82d638ddae3c1bd791dd3203d68bf439a3fc4af7db68fc25620e2fd3769717eb
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 indicator of malicious intent. The presence of dangerous formula APIs like RUN suggests the macro is designed to execute arbitrary code. While the exact payload is truncated, the mechanism points to a downloader or initial execution stage.

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) 6796 bytes
SHA-256: bd00e2d93519cf392c7576b37e6e92ebef3b1766e2be79ce22ed775eddeb2afc
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     17 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  AJWiirRb
' 0018     26 LABEL : Cell Value, String Constant - aghOrSyWtac len=0 
' 0018     22 LABEL : Cell Value, String Constant - AJbDzEM len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B182 
' 0018     22 LABEL : Cell Value, String Constant - dmdZmba len=0 
' 0018     27 LABEL : Cell Value, String Constant - EggdcLCWdhnM len=0 
' 0018     25 LABEL : Cell Value, String Constant - gvuoivhSHi len=0 
' 0018     25 LABEL : Cell Value, String Constant - gwoAQoPwru len=0 
' 0018     24 LABEL : Cell Value, String Constant - HYXmbYFhe len=0 
' 0018     25 LABEL : Cell Value, String Constant - jtajRCWROS len=0 
' 0018     20 LABEL : Cell Value, String Constant - KroCF len=0 
' 0018     24 LABEL : Cell Value, String Constant - kYymtOnDO len=0 
' 0018     25 LABEL : Cell Value, String Constant - nrrhkXmwem len=0 
' 0018     26 LABEL : Cell Value, String Constant - nXQbuUIQdSr len=0 
' 0018     25 LABEL : Cell Value, String Constant - OfXKuWXaha len=0 
' 0018     22 LABEL : Cell Value, String Constant - oysmDkk len=0 
' 0018     25 LABEL : Cell Value, String Constant - rjSyeRnvQT len=0 
' 0018     27 LABEL : Cell Value, String Constant - sPcgJKWQKHZy len=0 
' 0018     25 LABEL : Cell Value, String Constant - TMSxOxAhet len=0 
' 0018     27 LABEL : Cell Value, String Constant - uzMWWAVscHka len=0 
' 0018     20 LABEL : Cell Value, String Constant - WrCnW len=0 
' 0018     25 LABEL : Cell Value, String Constant - YLPCuciPbZ 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 Const
... (truncated)

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