Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 ee3cbe4e815c267b…

MALICIOUS

Office (OLE)

184.0 KB Created: 2020-07-14 03:33:56 Authoring application: Microsoft Excel First seen: 2020-09-15
MD5: 04f02d35add866cb0cc05a98f7a4a06e SHA-1: 6855a22e88dd4d81ced56e2f34da873a1f7e7791 SHA-256: ee3cbe4e815c267b41df56612167f775a3cea880db8ee66980a8f81219cbb450
220 Risk Score

Malware Insights

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

The file contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a critical finding. The presence of dangerous formula APIs and environment evasion techniques suggests malicious intent. The macro sheet likely attempts to download and execute a second-stage payload, a common tactic for initial compromise via spearphishing attachments.

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) 61424 bytes
SHA-256: 7df5a445ee08ca89281fc586530fd826486e43d74487298a7b79404c23fcbfb6
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 -  zLtsgStQcqYpbfG
' 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     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0018     51 LABEL : Cell Value, String Constant - aHNgoeKFFEJtmtYykBEHyXBfPLzULCPZJIvh len=0 
' 0018     23 LABEL : Cell Value, String Constant - aILfIMaW len=0 
' 0018     21 LABEL : Cell Value, String Constant - aJIviJ len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  !BL47449 
' 0018     28 LABEL : Cell Value, String Constant - avxHeLoFlrLTI len=0 
' 0018     45 LABEL : Cell Value, String Constant - bcafQJQuWHXbdVuXCmhWqhYmwfeSEf len=0 
' 0018     24 LABEL : Cell Value, String Constant - BfQMzULCQ len=0 
' 0018     27 LABEL : Cell Value, String Constant - BHDOfgCENkRu len=0 
' 0018     20 LABEL : Cell Value, String Constant - BKKJO len=0 
' 0018     23 LABEL : Cell Value, String Constant - brvxpPrW len=0 
' 0018     51 LABEL : Cell Value, String Constant - BuNKgDbTPbsHcQZwrVXEYdlbHQQOTqxFjvvL len=0 
' 0018     22 LABEL : Cell Value, String Constant - BVMDQbK len=0 
' 0018     59 LABEL : Cell Value, String Constant - BvvuzkdkPpbruxpOrWGCqLCsGQzymYzWiwevhlMzxrKH len=0 
' 0018     47 LABEL : Cell Value, String Constant - BXHSXUfwLTUdCwZbIOhpfLGHFKuCJZBz len=0 
' 0018     49 LABEL : Cell Value, String Constant - BXtSKGSixTHQniMOuOUcRwGHFKhnvZmlCG len=0 
' 0018     23 LABEL : Cell Value, String Constant - ccafRXev len=0 
' 0018     23 LABEL : Cell Value, String Constant - CcnhzjGp len=0 
' 0018     59 LABEL : Cell Value, String Constant - CKyeaaZePVdtUTjZcUsWBygVpfWkuddQRltHiChGXjXV len=0 
' 0018     29 LABEL : Cell Value, String Constant - COcKbOSrfdXpmJ len=0 
' 0018     20 LABEL : Cell Value, String Constant - CppRZ len=0 
' 0018     32 LABEL : Cell Value, String Constant - dbgELSvJIYcfWvLDn len=0 
' 0018     23 LABEL : Cell Value, String Constant - dcsvyqPe len=0 
' 0018     45 LABEL : Cell Value, String Constant - DDdmybuaxQpQbVnWtdntpCShoqzXSv len=0 
' 0018     34 LABEL : Cell Value, String Constant - dfMfltiOXYWbyFMqEDT len=0 
' 0018     46 LABEL : Cell Value, String Constant - DGxWleOvyTvzOLtHggIQcFYEbtTtFyR len=0 
' 
... (truncated)