Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 fe489fc40933ce39…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-25 10:28:19 Authoring application: Microsoft Excel First seen: 2021-09-16
MD5: bd05d3bbdb3a5f1090c3addabc1c645a SHA-1: 77a4fd0f2fe2322c499b36cf90c96477b56ae8e4 SHA-256: fe489fc40933ce3972f124eb3b8186d38a149fbbeaa96182b6e69e0ce0722b65
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 macro, which is a critical finding indicating potential for arbitrary code execution. The presence of dangerous formula APIs further supports this. The macro sheet itself is named 'PenfUnDfUt', and the Auto_Open entry is a key indicator of malicious intent, likely to download and execute 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) 6730 bytes
SHA-256: a4dad840f11ee4d42655f7fc5563a8161e90343b37b0cf63015cae027804c3f7
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 -  PenfUnDfU
' 0018     21 LABEL : Cell Value, String Constant - adUUum len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!F174 
' 0018     23 LABEL : Cell Value, String Constant - bAqIfQUp len=0 
' 0018     21 LABEL : Cell Value, String Constant - dEzsds len=0 
' 0018     26 LABEL : Cell Value, String Constant - dsnhwvORARg len=0 
' 0018     27 LABEL : Cell Value, String Constant - dtqjNpjDSYXw len=0 
' 0018     24 LABEL : Cell Value, String Constant - eCbyYEVqq len=0 
' 0018     20 LABEL : Cell Value, String Constant - eqIWz len=0 
' 0018     24 LABEL : Cell Value, String Constant - GdpZbxqFb len=0 
' 0018     21 LABEL : Cell Value, String Constant - GKrsKC len=0 
' 0018     24 LABEL : Cell Value, String Constant - LxqnfyBIi len=0 
' 0018     27 LABEL : Cell Value, String Constant - MtsAUmwYZfUW len=0 
' 0018     21 LABEL : Cell Value, String Constant - NCADxq len=0 
' 0018     27 LABEL : Cell Value, String Constant - OhvPELHDKDkz len=0 
' 0018     26 LABEL : Cell Value, String Constant - OPmMGbxjMyY len=0 
' 0018     21 LABEL : Cell Value, String Constant - TwemZl len=0 
' 0018     27 LABEL : Cell Value, String Constant - uKhaHbgJLyPQ len=0 
' 0018     26 LABEL : Cell Value, String Constant - wjoXfhoWwjd len=0 
' 0018     26 LABEL : Cell Value, String Constant - wQYJeRIunJh len=0 
' 0018     23 LABEL : Cell Value, String Constant - zpjJkSeB len=0 
' 0018     24 LABEL : Cell Value, String Constant - ZqjWvChwX 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/ SS
... (truncated)

Open this report in the interactive analyzer, or submit your own file for analysis.