Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 4ae105965dafc9b9…

MALICIOUS

Office (OLE)

205.5 KB Created: 2020-07-16 08:15:40 Authoring application: Microsoft Excel First seen: 2020-09-07
MD5: db7b58e5777e6ab5c965fe6d79f443dc SHA-1: dbd752010cae17ddb9548b572ef703f21c6f93ff SHA-256: 4ae105965dafc9b9e145f0f8dc1fc82327da503509d94740ed5e564cf6d8accd
220 Risk Score

Malware Insights

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

This Excel 4.0 macro sheet contains an Auto_Open macro, which is designed to execute automatically when the workbook is opened. The presence of environment evasion and a lure to enable macros indicates a malicious intent to execute further payloads. The macro uses dangerous formula APIs and attempts to evade detection.

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) 89865 bytes
SHA-256: 6875bfbdf36c8510cd17bdc43dc45016f28a68d3f8d7c863fe2df543134cce8e
Preview script
First 1,000 lines of the extracted script
' 0085     10 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  o
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     20 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  btqNjIOKVYn
' 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     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0018     31 LABEL : Cell Value, String Constant - ajHCfhOUnvlRMMLQ len=0 
' 0018     53 LABEL : Cell Value, String Constant - aKUaWizBWXgElPeLRksiOJKINxqxcDoFILDcFj len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  o!DU53916 
' 0018     41 LABEL : Cell Value, String Constant - bhBJxdZZYcOUcsTSiYbTrVzxfU len=0 
' 0018     59 LABEL : Cell Value, String Constant - bIlBhoHPFkfgejVOVyaLbfiZybHqmbvlcqBjjWJjGThP len=0 
' 0018     38 LABEL : Cell Value, String Constant - BIPfGGVLOGeImkSHbSJWgQP len=0 
' 0018     46 LABEL : Cell Value, String Constant - BKFixRkEynTcdbgRLSvJIYcfWvLDnVX len=0 
' 0018     23 LABEL : Cell Value, String Constant - BsRgZJrt len=0 
' 0018     58 LABEL : Cell Value, String Constant - BuNKhDbTQbsHcQZxrVXEYdlbHQQPUqxFjwvMPSKixqa len=0 
' 0018     37 LABEL : Cell Value, String Constant - BuNKhDbUQbsHcQaxsWXEYd len=0 
' 0018     46 LABEL : Cell Value, String Constant - bVnXtdntpCThpqzXSvxekEMChcdbgRY len=0 
' 0018     21 LABEL : Cell Value, String Constant - CbCNHZ len=0 
' 0018     20 LABEL : Cell Value, String Constant - CDNWR len=0 
' 0018     24 LABEL : Cell Value, String Constant - CdxcBSsTe len=0 
' 0018     18 LABEL : Cell Value, String Constant - CFZ len=0 
' 0018     37 LABEL : Cell Value, String Constant - CGUQzNmmOWiLeKhzZzLFXH len=0 
' 0018     21 LABEL : Cell Value, String Constant - COefBD len=0 
' 0018     55 LABEL : Cell Value, String Constant - CriwHppcdENZCVzYqCqnhzwUEOUQcstPRaxfIYFL len=0 
' 0018     61 LABEL : Cell Value, String Constant - CRmnxHCfuOhBvkQZaYdOIPsGFVZbTsIzkSUpSWkuPdQDdz len=0 
' 0018     22 LABEL : Cell Value, String Constant - CrXSSRW len=0 
' 0018     20 LABEL : Cell Value, String Constant - DBGqj len=0 
' 0018     64 LABEL : Cell Value, String Constant - dbJxSIyNXGGssUcpRlQoGSHExQNjTekgrJKfhqOuYoVbuDrXT len=0 
' 0018     37 LABEL : Cell Value, String Constant - DDemybuaxQcQOIaXtdotpC len=0 
' 0018     62 LABEL : Cell Value, String Constant - DENXSvLdxRLBgpqoteXeJWVlorjJXQBikFhmzLfsgStQPqY len=0 
' 0018     38 LABEL : Cell Value, String Constant - DexdCTfTRLdawgrxtFWXstE len=0 
' 0018     49 LABEL : Cell Value, String Constant - DNkfJKqLQYOtDECHekrWjiyCFwWkdOvxSu len=0 
' 0018     30 LABEL : Cell Value, String Constant - dNYdalDRZajICfh len=0 
' 0018     59 LABEL : Cell Value, String Constant - DPfgCENkSvLrxRZPuppoteXeJjVlorjIlQzvkFvmzKts len=0 
' 0018     41 LABEL : Cell Value, String Constant - DpQmyNuMyDcQOIaXtQouqCFUpq len=0 
' 0018     22 LABEL : Cell Value, String Constant - dWdIiUk len=0 
' 0018     23 LABEL : Cell Value, String Constant - DyKbqxzJ len=0 
' 0018     22 LABEL : Cell Value, String Constant - DymHxoD len=0 
' 0018     24 LABEL : Cell Value, String Constant - dyzKTOrHa len=0 
' 0018     17 LABEL : Cell Value, String Constant - dz len=0 
' 0018     18 LABEL : Cell Value, String Constant - ejU len=0 
' 0018     19 LABEL : Cell Value, String Constant - eJWV len=0 
' 0018     56 LABEL : Cell Value, String Constant - embHDDCHrkrWwiyCFwVydNJxSJzNXGGtfHdpElDos len=0 
' 0018     21 LABEL : Cell Value, String Constant - EulyJs len=0 
' 
... (truncated)