Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 5795f5e41c5ca9d2…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:40:11 Authoring application: Microsoft Excel First seen: 2021-09-23
MD5: b79ded2d1f95b47dd5a9ab280f4665d4 SHA-1: 265a63f7892219e2a56df4b7c7d188504c2ee886 SHA-256: 5795f5e41c5ca9d2006dfe2d77bffd6dee220691dab0a8da64172fe60202c251
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic

The file contains Excel 4.0 (XLM) macros, specifically an Auto_Open defined name, which is a critical indicator of malicious intent. This technique allows for the execution of arbitrary commands upon opening the workbook, likely to download and execute a secondary payload. The presence of dangerous formula APIs further supports this assessment.

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) 6704 bytes
SHA-256: dd6c10d702482955e3e54fe24632ed690cda984be5d54bbd348eb7a773ab1a9f
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     15 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  Jtzyku
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!C182 
' 0018     27 LABEL : Cell Value, String Constant - BxuVVYRTXqpv len=0 
' 0018     24 LABEL : Cell Value, String Constant - BzSLuACqO len=0 
' 0018     26 LABEL : Cell Value, String Constant - dIhFsxrFjmV len=0 
' 0018     27 LABEL : Cell Value, String Constant - fbPfvbRHcvbO len=0 
' 0018     27 LABEL : Cell Value, String Constant - GfCTdxhXpRNN len=0 
' 0018     21 LABEL : Cell Value, String Constant - IuaZin len=0 
' 0018     21 LABEL : Cell Value, String Constant - iyYnLP len=0 
' 0018     20 LABEL : Cell Value, String Constant - JdFYH len=0 
' 0018     24 LABEL : Cell Value, String Constant - JFWtXYZff len=0 
' 0018     20 LABEL : Cell Value, String Constant - kvCaq len=0 
' 0018     22 LABEL : Cell Value, String Constant - lcPsgnR len=0 
' 0018     21 LABEL : Cell Value, String Constant - lCxOse len=0 
' 0018     26 LABEL : Cell Value, String Constant - uxKHQIEZgai len=0 
' 0018     20 LABEL : Cell Value, String Constant - vCUAf len=0 
' 0018     24 LABEL : Cell Value, String Constant - XcMPCqSKY len=0 
' 0018     22 LABEL : Cell Value, String Constant - xqFwkUE len=0 
' 0018     21 LABEL : Cell Value, String Constant - xRoljq len=0 
' 0018     23 LABEL : Cell Value, String Constant - YJnFhENt len=0 
' 0018     24 LABEL : Cell Value, String Constant - ySGmbWuPp len=0 
' 0018     20 LABEL : Cell Value, String Constant - YtiAD 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 LABELS
... (truncated)

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