Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 880f4c7276e7eeff…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:34:47 Authoring application: Microsoft Excel First seen: 2021-07-02
MD5: fac61c3a5ea5bbd929c70f6a7ef9de32 SHA-1: d667b5eb2d7b08d859931c6f92f8214d0e29759d SHA-256: 880f4c7276e7eeffce3cca036223c8f6c68c1a0a6085806cef2d9b26d2e73b5f
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 entry, which is a critical finding indicating automatic execution upon opening. The presence of dangerous formula APIs like RUN suggests the macro is designed to execute arbitrary commands, likely to download and run a second-stage payload. The document body contains heavily obfuscated text, further supporting a malicious intent.

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) 6669 bytes
SHA-256: c5e5a5950a8b270b819fa887a493c07fa7d1b405478d89d6bf92bd8ba06358b6
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 -  DhzOoIRhT
' 0018     26 LABEL : Cell Value, String Constant - atCyOTDXIqw len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!F157 
' 0018     26 LABEL : Cell Value, String Constant - BlnYBxLGyaX len=0 
' 0018     26 LABEL : Cell Value, String Constant - dAVQqJNuFRn len=0 
' 0018     20 LABEL : Cell Value, String Constant - dePvX len=0 
' 0018     23 LABEL : Cell Value, String Constant - DXZdicWu len=0 
' 0018     23 LABEL : Cell Value, String Constant - gniCDQdk len=0 
' 0018     25 LABEL : Cell Value, String Constant - GsfeVHjcpM len=0 
' 0018     27 LABEL : Cell Value, String Constant - HxIIIFarDaBu len=0 
' 0018     22 LABEL : Cell Value, String Constant - JAcDjKV len=0 
' 0018     20 LABEL : Cell Value, String Constant - JBFEX len=0 
' 0018     26 LABEL : Cell Value, String Constant - KDnNSmobORX len=0 
' 0018     23 LABEL : Cell Value, String Constant - KDYTtfkW len=0 
' 0018     25 LABEL : Cell Value, String Constant - kRCMTvjQnU len=0 
' 0018     23 LABEL : Cell Value, String Constant - mrBvfNTM len=0 
' 0018     24 LABEL : Cell Value, String Constant - nahNbntgl len=0 
' 0018     27 LABEL : Cell Value, String Constant - NBKqxwPoKuWN len=0 
' 0018     23 LABEL : Cell Value, String Constant - nXfkeRdF len=0 
' 0018     25 LABEL : Cell Value, String Constant - QHRvpxEdGb len=0 
' 0018     25 LABEL : Cell Value, String Constant - vOQVHadHmI len=0 
' 0018     20 LABEL : Cell Value, String Constant - ymTSU 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/ SS
... (truncated)

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