Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 d3485982cffbeb89…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-25 10:35:38 Authoring application: Microsoft Excel First seen: 2020-12-25
MD5: 4d7d0ef1f0777c7eb3f6a5c9c0dda59c SHA-1: 47cc5e9c72cff49db6bc7fb255edf2a26b1454d1 SHA-256: d3485982cffbeb891488e33d22aabb9b03602c228d971ec8c0e1f38815305a42
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 function, which is a known method for executing malicious code upon opening the workbook. The critical heuristics indicate the presence of dangerous formula APIs within the Auto_Open macro, suggesting it's designed to run arbitrary commands. No specific IOCs like URLs or hashes were extracted, but the technique itself is highly indicative of 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) 6510 bytes
SHA-256: d88284717e72a4552d393f0807f61337334829536e1bbda6f42d0821a37f4e84
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 -  VPkbsuEm
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H190 
' 0018     27 LABEL : Cell Value, String Constant - BWCMAYeowzRR len=0 
' 0018     24 LABEL : Cell Value, String Constant - fKKrbUpHV len=0 
' 0018     23 LABEL : Cell Value, String Constant - JppzhweN len=0 
' 0018     25 LABEL : Cell Value, String Constant - JZnMklPZeP len=0 
' 0018     25 LABEL : Cell Value, String Constant - KxlUFHrvwv len=0 
' 0018     23 LABEL : Cell Value, String Constant - LDMmIzZW len=0 
' 0018     20 LABEL : Cell Value, String Constant - LqdvQ len=0 
' 0018     21 LABEL : Cell Value, String Constant - NrlEhd len=0 
' 0018     23 LABEL : Cell Value, String Constant - OCskZqkt len=0 
' 0018     26 LABEL : Cell Value, String Constant - rSVUxMOvEdX len=0 
' 0018     23 LABEL : Cell Value, String Constant - SBiVOwJA len=0 
' 0018     26 LABEL : Cell Value, String Constant - SlleSDVocGs len=0 
' 0018     26 LABEL : Cell Value, String Constant - TuFhCtSmHhf len=0 
' 0018     20 LABEL : Cell Value, String Constant - uSRCr len=0 
' 0018     22 LABEL : Cell Value, String Constant - VcTssjU len=0 
' 0018     21 LABEL : Cell Value, String Constant - wXMaOy len=0 
' 0018     21 LABEL : Cell Value, String Constant - YDKQBU len=0 
' 0018     20 LABEL : Cell Value, String Constant - YPHWL len=0 
' 0018     21 LABEL : Cell Value, String Constant - ZoOQhD len=0 
' 0018     20 LABEL : Cell Value, String Constant - ZwCqT 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 LABELSS
... (truncated)

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