Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 3dd4d7174cee7812…

MALICIOUS

Office (OLE)

180.0 KB Created: 2020-07-14 04:14:49 Authoring application: Microsoft Excel First seen: 2020-09-07
MD5: 282592bc2dcafaf38c41a5f541845f1f SHA-1: 9199f70332883aac32e37b9056106984c7872c48 SHA-256: 3dd4d7174cee7812c97c4ecdf3b1c28c2cd93dafffffb69c0e32632e6f32bbe3
220 Risk Score

Malware Insights

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

The sample is an Excel 4.0 macro-enabled document containing an Auto_Open function, which is a critical finding indicating automatic execution upon opening. The presence of dangerous formula APIs and environment evasion techniques suggests malicious intent. The document body contains obfuscated strings, and while no direct URLs or executable payloads were extracted, the Auto_Open macro is designed to execute arbitrary code, likely downloading and running a second-stage 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) 61519 bytes
SHA-256: a0396219674b8e275a329dfdfa03fd543645442ff8783cd6220e9851d3b24cdc
Preview script
First 1,000 lines of the extracted script
' 0085     10 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  v
' 0085     24 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  DuTwbZHvQHxLVEE
' 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     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 Value, String Constant - DmxEzL len=0 
' 0018     24 LABEL : Cell Value, String Constant - DNvviVvSf len=0 
' 0018     23 LABEL : Cell Value, String Constant - dnwrVlEY len=0 
' 0018     24 LABEL : Cell Value, String Constant - doGUcdnLG len=0 
' 0018     21 LABEL : Cell Value, String Constant - dWdIUT len=0 
' 0018     33 LABEL : Cell Value, String Constant - dWHoqLnsGQlymYzWVw len=0 
' 0018     20 LABEL : Cell Value, String Constant - DxbqK len=0 
' 0018     21 LABEL : Cell Value, String Constant - DynIxo len=0 
' 0018     21 LABEL : Cell Value, String Constant - ejUNUy len=0 
' 0018     39 LABEL : Cell Value, String Constant - eKFGEJunuZzkBFIyYBgQMBVL len=0 
' 0018     23 LABEL : Cell Value, String Constant - eKhzMzxr
... (truncated)