Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 33a6b879b2d8dc15…

MALICIOUS

Office (OLE)

36.5 KB Created: 2020-11-25 10:44:36 Authoring application: Microsoft Excel First seen: 2021-05-26
MD5: 2d8dd1ed39358328dfeb6ced3c8e9757 SHA-1: 4c69a0cd38527062712559bd9466c8d1a8e32988 SHA-256: 33a6b879b2d8dc15dcc7565fbb2eebc060bb99a4032c935b8050a62582b8d2fc
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 defined name, which is a known method for executing malicious code upon opening the workbook. The presence of dangerous formula APIs like RUN indicates the macro is designed to execute external commands or download payloads. No specific family could be identified, but the technique is common for initial execution.

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) 6703 bytes
SHA-256: fdd66761736165b5deaf988e2501839e2a90ef63f47e51adac8e532db7b514ae
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     20 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  VWGSFKxiwkc
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!H179 
' 0018     22 LABEL : Cell Value, String Constant - aVggnPF len=0 
' 0018     22 LABEL : Cell Value, String Constant - ClWvYbU len=0 
' 0018     23 LABEL : Cell Value, String Constant - DmdrMiXe len=0 
' 0018     20 LABEL : Cell Value, String Constant - FGItg len=0 
' 0018     20 LABEL : Cell Value, String Constant - GReKE len=0 
' 0018     26 LABEL : Cell Value, String Constant - jbRqWrgnVGl len=0 
' 0018     20 LABEL : Cell Value, String Constant - jdyTk len=0 
' 0018     24 LABEL : Cell Value, String Constant - NHWYuSFgl len=0 
' 0018     26 LABEL : Cell Value, String Constant - nhZoGzwAftM len=0 
' 0018     26 LABEL : Cell Value, String Constant - OJVTvLVNLVs len=0 
' 0018     24 LABEL : Cell Value, String Constant - PkPDQNJaf len=0 
' 0018     21 LABEL : Cell Value, String Constant - TOMELt len=0 
' 0018     26 LABEL : Cell Value, String Constant - uWfNQMnbRev len=0 
' 0018     22 LABEL : Cell Value, String Constant - VFVjHnG len=0 
' 0018     26 LABEL : Cell Value, String Constant - vWUYDSAJAUA len=0 
' 0018     26 LABEL : Cell Value, String Constant - XASPRXAYkuE len=0 
' 0018     26 LABEL : Cell Value, String Constant - XBJmrfwDehs len=0 
' 0018     27 LABEL : Cell Value, String Constant - XrYQucASzHlV len=0 
' 0018     21 LABEL : Cell Value, String Constant - yFkIvf len=0 
' 0018     21 LABEL : Cell Value, String Constant - YHqQCu 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
... (truncated)

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