Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 9280479d6e030e96…

MALICIOUS

Office (OLE)

174.0 KB Created: 2020-07-08 02:35:04 Authoring application: Microsoft Excel First seen: 2020-09-15
MD5: fcb24994ece22f8d6a2902790ad97aa5 SHA-1: b3d54d0b90522c189c7f29ed260333c08c91ea08 SHA-256: 9280479d6e030e96b14aa0c2aa5e856f475e657d11d2d1596c082ff157d916c9
220 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment

The file contains Excel 4.0 (XLM) macros, including an Auto_Open defined name, which is a strong indicator of malicious intent. The heuristics indicate the presence of dangerous formula APIs and environment evasion techniques within the macro. The macro sheet likely attempts to trick the user into enabling macros, a common lure for malware droppers.

Heuristics 5

  • 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.
  • XLM Auto_Open environment-evasion close gate critical OLE_XLM_ENVIRONMENT_EVASION_CLOSE
    Excel 4.0 macro sheet auto-executes environment checks with GET.WORKSPACE / GET.WINDOW, then shows a fake corruption/error message and closes the workbook when the host fails those checks. This is a malware sandbox-evasion pattern, even when the later payload stage is hidden behind obfuscated defined-name flow.
  • 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.
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

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) 49549 bytes
SHA-256: 61a9fe4f1e099855f5f9103eb0ab59c60061618d0a954c1da097bcefe7341886
Preview script
First 1,000 lines of the extracted script
' 0085      9 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  
' 0085     24 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  opnsdXeIjUkoqiI
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet1
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet1
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet1
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet1
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet1
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet1
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet1
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet1
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet1
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet1
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet2
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet2
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet2
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet2
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet2
' 0085     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet2
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  !BV5730 
' 0018     23 LABEL : Cell Value, String Constant - aWLfVMak len=0 
' 0018     17 LABEL : Cell Value, String Constant - aX len=0 
' 0018     22 LABEL : Cell Value, String Constant - axhrxtG len=0 
' 0018     38 LABEL : Cell Value, String Constant - bgdoGHcdmLrVkRXqyoUPQOT len=0 
' 0018     41 LABEL : Cell Value, String Constant - BgEWiWUOgdzjuzwIZavwGeLoEk len=0 
' 0018     44 LABEL : Cell Value, String Constant - BHPfGFVLOGeImkSHbRIWgPPCDdmyb len=0 
' 0018     22 LABEL : Cell Value, String Constant - bIOhpfL len=0 
' 0018     48 LABEL : Cell Value, String Constant - biyZYoehZxbGElaulbpziiVWwGSuOsRjv len=0 
' 0018     55 LABEL : Cell Value, String Constant - BLRNZpFMOXupTVCIbjZFzzyEovDTttJyCtSvaYGu len=0 
' 0018     42 LABEL : Cell Value, String Constant - bQkbSfpYYMMmvIkEjHZlZWQifDm len=0 
' 0018     31 LABEL : Cell Value, String Constant - BsRuZXFtOFvJTDCp len=0 
' 0018     50 LABEL : Cell Value, String Constant - bUbGTSilogGUNxfhCejwIcpdPqNMnVmYcDd len=0 
' 0018     23 LABEL : Cell Value, String Constant - bVnkHdCt len=0 
' 0018     22 LABEL : Cell Value, String Constant - BWJTqlP len=0 
' 0018     39 LABEL : Cell Value, String Constant - bWnlIdCuqCThEqBYTwxeyEMC len=0 
' 0018     51 LABEL : Cell Value, String Constant - CcbrhkcBeJHodxnesDllYYzIVwRvUlxmjdvs len=0 
' 0018     35 LABEL : Cell Value, String Constant - cDZYBhzlpPpBuNKgDbTP len=0 
' 0018     23 LABEL : Cell Value, String Constant - CGIzZogR len=0 
' 0018     19 LABEL : Cell Value, String Constant - chFM len=0 
' 0018     22 LABEL : Cell Value, String Constant - ChFXjXU len=0 
' 0018     28 LABEL : Cell Value, String Constant - CosSGExQNjGek l
... (truncated)