Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 d78042b9c0e57377…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:42:09 Authoring application: Microsoft Excel First seen: 2021-10-14
MD5: 6d17600087dad0443aedaef0f7a802af SHA-1: 1c761be5e40cc751ad9938f8131bc7ca82959017 SHA-256: d78042b9c0e573779945fcc5f295a3b21d69f65bc7931b3477127d0aadd529b9
140 Risk Score

Malware Insights

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

The file contains Excel 4.0 (XLM) macros, specifically an Auto_Open defined name, which is a critical indicator of malicious intent. The presence of dangerous formula APIs like RUN in the XLM macros suggests the macro is designed to execute arbitrary code. This functionality is commonly used to download and execute a second-stage payload, making the initial file a downloader.

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) 6632 bytes
SHA-256: 37092887af11c5e54b53867305fcc2a8f67713459727b38795552e14f24a9b3c
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     20 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  rtCFttEQjjY
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!F165 
' 0018     22 LABEL : Cell Value, String Constant - BnqqqcD len=0 
' 0018     22 LABEL : Cell Value, String Constant - BXYbQlI len=0 
' 0018     24 LABEL : Cell Value, String Constant - cweDAKXKd len=0 
' 0018     25 LABEL : Cell Value, String Constant - DVNBclvtsB len=0 
' 0018     26 LABEL : Cell Value, String Constant - EbqKoHhlvDh len=0 
' 0018     25 LABEL : Cell Value, String Constant - ffiGvLIRLd len=0 
' 0018     23 LABEL : Cell Value, String Constant - jzNiECgd len=0 
' 0018     21 LABEL : Cell Value, String Constant - kZSqYb len=0 
' 0018     21 LABEL : Cell Value, String Constant - LEhoPl len=0 
' 0018     27 LABEL : Cell Value, String Constant - LfvQtvDPseed len=0 
' 0018     25 LABEL : Cell Value, String Constant - lokyHNHgLm len=0 
' 0018     22 LABEL : Cell Value, String Constant - MvmQIri len=0 
' 0018     21 LABEL : Cell Value, String Constant - mwRoIg len=0 
' 0018     20 LABEL : Cell Value, String Constant - RjOLx len=0 
' 0018     27 LABEL : Cell Value, String Constant - ROZafiknwfcA len=0 
' 0018     24 LABEL : Cell Value, String Constant - sHDlXpKNk len=0 
' 0018     22 LABEL : Cell Value, String Constant - VlGYsas len=0 
' 0018     21 LABEL : Cell Value, String Constant - ygJdyx len=0 
' 0018     21 LABEL : Cell Value, String Constant - yjVtcG len=0 
' 0018     23 LABEL : Cell Value, String Constant - YtBPSnUf 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     10
... (truncated)

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