Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 d4ead54b78d9f30e…

MALICIOUS

Office (OLE)

202.0 KB Created: 2020-07-14 04:14:49 Authoring application: Microsoft Excel First seen: 2020-09-15
MD5: fa92c20908e2b38af5bd1a2da3624822 SHA-1: 284d0f8f86d88745149775d101ebeb354911ffa7 SHA-256: d4ead54b78d9f30e5188cc8f41bc059e37b2dcd2d0f750eafef6c190ef8322b8
220 Risk Score

Malware Insights

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

The sample is an Excel file containing Excel 4.0 (XLM) macros, indicated by multiple critical heuristic firings including OLE_XLM_AUTOOPEN and OLE_XLM_DANGEROUS_FN. The presence of an Auto_Open entry suggests the macro will execute automatically upon opening the document. The heuristic OLE_XLM_ENVIRONMENT_EVASION_CLOSE indicates attempts to evade detection. The SE_ENABLE_LURE heuristic suggests the document prompts the user to enable macros, a common social engineering tactic for malware delivery.

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) 81883 bytes
SHA-256: 171be2eee7be7024d1cd3d61e237d357eefbdc517c69ce38e1d139d36854ec2c
Preview script
First 1,000 lines of the extracted script
' 0085     10 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  v
' 0085     18 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  BRHKCaEig
' 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     15 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet2
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0018     22 LABEL : Cell Value, String Constant - aHkBhnH len=0 
' 0018     64 LABEL : Cell Value, String Constant - aHPQOTExFivuLPSJixqaIKfIMakFTGsTpoRxQCGfGRLdawTrj len=0 
' 0018     64 LABEL : Cell Value, String Constant - aoyhhUUvERsMrQhtifZroLuGMITklHISpWzQvDWeTyuusxjcj len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  v!DZ20620 
' 0018     21 LABEL : Cell Value, String Constant - aXtPot len=0 
' 0018     22 LABEL : Cell Value, String Constant - azPHrZb len=0 
' 0018     24 LABEL : Cell Value, String Constant - bMtvQsxMW len=0 
' 0018     17 LABEL : Cell Value, String Constant - BN len=0 
' 0018     25 LABEL : Cell Value, String Constant - BPZtIuhIed len=0 
' 0018     31 LABEL : Cell Value, String Constant - bXjBPXYhFzdfMSlt len=0 
' 0018     21 LABEL : Cell Value, String Constant - cCeKHp len=0 
' 0018     49 LABEL : Cell Value, String Constant - cCRJtbdybftEYmZMmJIkRiVZyZkewtQmLD len=0 
' 0018     21 LABEL : Cell Value, String Constant - Cdcsil len=0 
' 0018     43 LABEL : Cell Value, String Constant - cdyzKhOrHnuNVLqlmkpaUbFgRhlo len=0 
' 0018     32 LABEL : Cell Value, String Constant - CjlGinBMgthTuRQrZ len=0 
' 0018     60 LABEL : Cell Value, String Constant - ClhWqgXlveeREeBOcKbNRqfcWolIeDJFQUiEGPYTwNfzT len=0 
' 0018     38 LABEL : Cell Value, String Constant - coRkQoGSGExQNjTekgrJKfg len=0 
' 0018     23 LABEL : Cell Value, String Constant - CPOeikcC len=0 
' 0018     53 LABEL : Cell Value, String Constant - cpoFILDbqjTBEYBFTdyMylNjhKrJuyZyKEWTqM len=0 
' 0018     52 LABEL : Cell Value, String Constant - CQaJJviJfsHoGrvVKHBTQmJhnjuyNiktDxbrK len=0 
' 0018   
... (truncated)