Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 d4436b5b08766d10…

MALICIOUS

Office (OLE)

249.5 KB Created: 2020-08-05 09:34:52 Authoring application: Microsoft Excel First seen: 2020-09-07
MD5: ac549a2a433c29e744955117dbc6c30b SHA-1: 12efbf2e91e3f170da9bf2431f51b9dcd6ff92b3 SHA-256: d4436b5b08766d10e8f57a71bfe72787c6ebf4d0680dfdb460fd59a6e3e3368e
180 Risk Score

Malware Insights

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

The sample is an Excel 4.0 macro-enabled document. Heuristics indicate the presence of an Auto_Open macro that uses dangerous functions and includes environment evasion checks. The document body attempts to socially engineer the user into enabling content, which would trigger the malicious XLM macro. No specific family could be identified.

Heuristics 4

  • 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 HALT gate high OLE_XLM_ENVIRONMENT_EVASION_HALT
    Excel 4.0 macro sheet auto-executes multiple GET.WORKSPACE / GET.WINDOW environment checks and halts execution when the host does not match the expected user environment. This is a common sandbox-evasion pattern in XLM malware and is stronger than a bare XLM macro-sheet indicator.
  • 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.

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) 267777 bytes
SHA-256: 1bd47e864490594d9be494dd99724d61ba4649d476de7a7b792ed976669be6c3
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     18 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  Qd0KKyX96
' 0018     31 LABEL : Cell Value, String Constant -           hidden len=7 ptgRef3d  Sheet!HC439 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open hidden len=7 ptgNameX  NAMEIDX 1 
' 0018     20 LABEL : Cell Value, String Constant - azxnW len=0 
' 0018     20 LABEL : Cell Value, String Constant - crkIh len=0 
' 0018     24 LABEL : Cell Value, String Constant - djnNwQYjb len=0 
' 0018     26 LABEL : Cell Value, String Constant - ebnSmhBKoRc len=0 
' 0018     26 LABEL : Cell Value, String Constant - ESCEqRAfvGj len=0 
' 0018     26 LABEL : Cell Value, String Constant - FivHauRkdwA len=0 
' 0018     23 LABEL : Cell Value, String Constant - hLGXfxCg len=0 
' 0018     22 LABEL : Cell Value, String Constant - HPsGJSm len=0 
' 0018     24 LABEL : Cell Value, String Constant - JcSvoGFCG len=0 
' 0018     27 LABEL : Cell Value, String Constant - MevGBEAircrK len=0 
' 0018     22 LABEL : Cell Value, String Constant - oziEBBY len=0 
' 0018     27 LABEL : Cell Value, String Constant - tPnBqjDiouUi len=0 
' 0018     23 LABEL : Cell Value, String Constant - tuKMfodJ len=0 
' 0018     21 LABEL : Cell Value, String Constant - WpvBVf len=0 
' 0018     22 LABEL : Cell Value, String Constant - yZWzrqC len=0 
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 00fd     10
... (truncated)