Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 d734a408ea753544…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:40:09 Authoring application: Microsoft Excel First seen: 2021-10-14
MD5: 42648e8a7a17ab9d3c6eeda13b742806 SHA-1: 4053e9a8d9eac4ef72ae36fd08d52932d9fd03e7 SHA-256: d734a408ea753544ad0136f73695381b88180bc8d08c31fa88e2447a3ea3e6cd
140 Risk Score

Malware Insights

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

The file is an Excel document containing Excel 4.0 macros, specifically an Auto_Open function. This function is known to be used to execute arbitrary code upon opening the document. The critical heuristics indicate the presence of dangerous formula APIs within the Auto_Open macro, suggesting it's designed to download and execute a secondary payload. No specific URLs or hashes were extracted, limiting further analysis of the payload.

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) 6630 bytes
SHA-256: 39a74ba3043003fcb583f7a6c77521a0346e62dc5babcd86d09054047fe6259c
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  ykbsR
' 0018     25 LABEL : Cell Value, String Constant - ajNhMYhFZM len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H141 
' 0018     24 LABEL : Cell Value, String Constant - bYpLPVyEM len=0 
' 0018     27 LABEL : Cell Value, String Constant - CRwCbKZYuOZC len=0 
' 0018     22 LABEL : Cell Value, String Constant - EmBQedK len=0 
' 0018     27 LABEL : Cell Value, String Constant - eniwCjOjUImL len=0 
' 0018     23 LABEL : Cell Value, String Constant - GCmYmKiT len=0 
' 0018     22 LABEL : Cell Value, String Constant - HFIWOJM len=0 
' 0018     21 LABEL : Cell Value, String Constant - HLltNf len=0 
' 0018     22 LABEL : Cell Value, String Constant - htxMnYE len=0 
' 0018     21 LABEL : Cell Value, String Constant - kZDCAR len=0 
' 0018     27 LABEL : Cell Value, String Constant - lRaIViOKVrud len=0 
' 0018     20 LABEL : Cell Value, String Constant - Lsrmw len=0 
' 0018     27 LABEL : Cell Value, String Constant - MfDqlzMBmVTE len=0 
' 0018     23 LABEL : Cell Value, String Constant - oCPoQCAn len=0 
' 0018     26 LABEL : Cell Value, String Constant - RDtnoRhQpti len=0 
' 0018     21 LABEL : Cell Value, String Constant - rRrTOV len=0 
' 0018     22 LABEL : Cell Value, String Constant - TAevKGJ len=0 
' 0018     20 LABEL : Cell Value, String Constant - TMyNe len=0 
' 0018     23 LABEL : Cell Value, String Constant - VvupmVqA len=0 
' 0018     25 LABEL : Cell Value, String Constant - zbGqCdYMyx 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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