Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 349424c17dd67932…

MALICIOUS

Office (OLE)

174.0 KB Created: 2020-07-08 02:35:04 Authoring application: Microsoft Excel First seen: 2020-07-24
MD5: 70655fedd8f8afc547c74b45bdf19464 SHA-1: 8a45f65d1a9f00ac18cc27ed5ce23dacff84c889 SHA-256: 349424c17dd67932ebdc465442aaf51333bba94f9c8554f77513daff462c2d85
220 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.005 Visual Basic T1203 Exploitation for Client Execution

The sample is an Excel 4.0 macro-enabled document that uses an 'enable lure' to prompt the user to enable macros. Upon enabling, the Auto_Open macro executes, which is known to be used for malicious purposes. The macro sheet contains dangerous formula APIs and environment evasion techniques, indicating it's designed to download and execute a secondary payload.

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) 53273 bytes
SHA-256: 86f6d1c20b7efba313826dd914fdfcd4215f7c2b6d15622c66a4141967cb51eb
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 -  hZybGqmavlcqBjj
' 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     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 len=0 
' 0018     17 LABEL : Cell Value, String Constant - Cr len=0 
' 0018     33 LABEL : Cell Value, String Constant - csZfyHvbXXWaMFMqRD len=0 
' 0018     32 LABEL : Cell Value, String Constant - DDemybuayQcQOIaXt len=0 
' 0018     60 LABEL : Cell Value, String Constant - dHIovOWMrmnlqbipGhgwmpgGiOLthDsjxIqqddFNaCVBZ len=0 
' 0018     39 LABEL : Cell Value, String Constant - dKSTRWHBIlyxOSVMlBtdLNiL len=0 
' 0018     50 LABEL : Cell Value, String Constant - DLBgppotQXeJWVlorjIXQzikFhmzwfsSStC len=0 
' 0018     63 LABEL : Cell Value, String Constant - dotqCTUpqzYFixekEMChcdbgRKSvXIYceWvYDnjXsiZnxggT len=0 
' 0018     20 LABEL : Cell Value, String Constant - DpRnl len=0 
' 0018     48 LABEL : Cell Value, String Constant - DSZbkIDgiPVowlSNNMRCJQgHGWMPHfJnl len=0 
' 0018     21 LABEL : Cell Value, String Constant - DTtsJy len=0 
' 0018     24 LABEL : Cell Value, String Constant - ECHrkrWwi len=0 
' 0018     50 LABEL : Cell Value, String Constant - EILCbqjTBEYBFTdyMylMihKrJuyYyKEWTpM len=0 
' 0018     17 LABEL : Cell Value, String Constant - eJ len=0 
' 0018     21 LABEL : Cell 
... (truncated)