Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 248ce4c2cc35245a…

MALICIOUS

Office (OLE)

198.0 KB Created: 2020-07-14 04:14:49 Authoring application: Microsoft Excel First seen: 2020-09-07
MD5: 3c8798b74e6b9b6516e7a44281cabfda SHA-1: 2e4bd0e114434fee9510ff13382d3bd87b5a6eb3 SHA-256: 248ce4c2cc35245a5f78177632d19b423c60934526a2869a2749abc07fabb2cf
280 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

This Excel file contains Excel 4.0 (XLM) macros, including an Auto_Open entry, which is a critical finding. The macros utilize dangerous formula APIs and employ environment evasion techniques, indicating a malicious dropper. The presence of a lure to enable macros further supports its malicious intent.

Heuristics 6

  • ClamAV: Xls.Dropper.Agent-8844156-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Dropper.Agent-8844156-0
  • 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) 79376 bytes
SHA-256: 33722c9a2f50edad7faa6a217b718d9bac58b0504e295c14342cee8f12a41ac7
Preview script
First 1,000 lines of the extracted script
' 0085     10 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  v
' 0085     25 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  hITNfczVtlitLZui
' 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     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     50 LABEL : Cell Value, String Constant - CsShaKruPrvKGoDccDMYBUzXpPpBuNwTDNT len=0 
' 0018     23 LABEL : Cell Value, String Constant - csvyqPeX len=0 
' 0018     25 LABEL : Cell Value, String Constant - cVcHhTjmph len=0 
' 0018     24 LABEL : Cell Value, String Constant - CVdTytusx len=0 
' 0018     24 LABEL : Cell Value, String Constant - CvOLiEcie len=0 
' 0018     22 LABEL : Cell Value, String Constant - CwacJci len=0 
' 0018     55 LABEL : Cell Value, String Constant - cwCKzfoonrPWdIUUjnqiHWPygjEgkyverRRsBNpJ len=0 
' 0018     52 LABEL : Cell Value, String Constant - dDIFQTiEFOYTwMfySNChqrpufYfKXWmqskKZR len=0 
' 0018     20 LABEL : Cell Value, String Constant - dgYwM len=0 
' 0018     48 LABEL : Cell Value, String Constant - DidechSZgwXXmdfXwZECjYsjanyhgUUvE len=0 
' 0018     21 LABEL : Cell V
... (truncated)