Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 bcc45a817c981e8f…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-27 11:38:55 Authoring application: Microsoft Excel First seen: 2021-06-04
MD5: dfb327369aeb8773ce61701158b1a088 SHA-1: afd401b3a9ad9b0cb05a57b4a23515a4981bf55a SHA-256: bcc45a817c981e8fdba4d422255ded8ce323d64ed59c5262a56933d262dc3f87
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, which is a common technique for executing malicious code upon opening. The presence of dangerous formula APIs like RUN indicates the macro is designed to execute external commands or download payloads. While the specific payload or target URL is not directly visible, the critical heuristics strongly suggest a downloader or initial execution stage.

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) 6795 bytes
SHA-256: c575b2bb6ea2b23f38e85e4e1ce948f0fbb406224a43fa5e1991798c47fda3fa
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 -  vhcZCLUQp
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!B160 
' 0018     21 LABEL : Cell Value, String Constant - dIpJHU len=0 
' 0018     27 LABEL : Cell Value, String Constant - DOZWkngHkzOD len=0 
' 0018     24 LABEL : Cell Value, String Constant - GcEqdRaNB len=0 
' 0018     24 LABEL : Cell Value, String Constant - gtUjQOtDz len=0 
' 0018     23 LABEL : Cell Value, String Constant - hnFREySk len=0 
' 0018     25 LABEL : Cell Value, String Constant - HoGhMJLmjv len=0 
' 0018     21 LABEL : Cell Value, String Constant - iTLmGg len=0 
' 0018     22 LABEL : Cell Value, String Constant - iWMFKpk len=0 
' 0018     26 LABEL : Cell Value, String Constant - jBicKrFTwUi len=0 
' 0018     20 LABEL : Cell Value, String Constant - JOwvs len=0 
' 0018     26 LABEL : Cell Value, String Constant - juWovrgbMTP len=0 
' 0018     23 LABEL : Cell Value, String Constant - kEqNZhLP len=0 
' 0018     26 LABEL : Cell Value, String Constant - kRwzEPlWRMJ len=0 
' 0018     21 LABEL : Cell Value, String Constant - peugSL len=0 
' 0018     24 LABEL : Cell Value, String Constant - RKpHyIQiV len=0 
' 0018     22 LABEL : Cell Value, String Constant - sqMkCmQ len=0 
' 0018     22 LABEL : Cell Value, String Constant - urunTYC len=0 
' 0018     20 LABEL : Cell Value, String Constant - VahoH len=0 
' 0018     24 LABEL : Cell Value, String Constant - wIlzXCLDk len=0 
' 0018     23 LABEL : Cell Value, String Constant - zhydmTzI 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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