Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 9f265c1d6e17988f…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:42:14 Authoring application: Microsoft Excel First seen: 2021-07-07
MD5: b62607354a5d62373a7faadb061aa33a SHA-1: 58688b55c08c0ebf5157516926e4e04be1787d14 SHA-256: 9f265c1d6e17988f5deee4dbe2ed4cca889624a06c8db4645a4fd5a5af215a8e
140 Risk Score

Malware Insights

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

The file is an Excel 4.0 macro-enabled workbook containing an Auto_Open function. This function is designed to execute arbitrary code upon opening, leveraging dangerous formula APIs. The presence of the Auto_Open entry and the use of risky functions indicate a malicious intent to execute code, likely to download and run a secondary 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) 6582 bytes
SHA-256: 99a8b630847a82934989a1e7e8fa1093de9fc92ad2fb9c8ba34c5424102f594a
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     12 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  xDD
' 0018     25 LABEL : Cell Value, String Constant - AMHGtxtNTh len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!F135 
' 0018     22 LABEL : Cell Value, String Constant - beQgZYT len=0 
' 0018     26 LABEL : Cell Value, String Constant - BIhbfXPmHEn len=0 
' 0018     27 LABEL : Cell Value, String Constant - bXYEauOsWFQV len=0 
' 0018     25 LABEL : Cell Value, String Constant - gkFQAvMUPy len=0 
' 0018     24 LABEL : Cell Value, String Constant - IaJTyXyQT len=0 
' 0018     26 LABEL : Cell Value, String Constant - IsGuYPYucoO len=0 
' 0018     27 LABEL : Cell Value, String Constant - KhAtUHwRTfme len=0 
' 0018     21 LABEL : Cell Value, String Constant - KocvuF len=0 
' 0018     27 LABEL : Cell Value, String Constant - lesdYmMaKhmI len=0 
' 0018     21 LABEL : Cell Value, String Constant - MBqFhT len=0 
' 0018     26 LABEL : Cell Value, String Constant - MOorABqyrPU len=0 
' 0018     25 LABEL : Cell Value, String Constant - NZfhgeNmwx len=0 
' 0018     26 LABEL : Cell Value, String Constant - OrZniTaKacd len=0 
' 0018     24 LABEL : Cell Value, String Constant - pKiwaroEq len=0 
' 0018     24 LABEL : Cell Value, String Constant - pyFySsKDC len=0 
' 0018     21 LABEL : Cell Value, String Constant - rEqPJH len=0 
' 0018     23 LABEL : Cell Value, String Constant - TdiGkSDl len=0 
' 0018     20 LABEL : Cell Value, String Constant - UlTye len=0 
' 0018     22 LABEL : Cell Value, String Constant - xoOdKcV 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
'
... (truncated)

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