Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 c5a8cb8dd417375c…

MALICIOUS

Office (OLE)

248.5 KB Created: 2020-08-05 15:22:22 Authoring application: Microsoft Excel First seen: 2020-09-07
MD5: 27c76051e59d101e46ffbda2e7a32588 SHA-1: 2b689ee4ae90ec7ee398b582334def80036f1592 SHA-256: c5a8cb8dd417375c253bfecc296b2200d7cc2d7f1820a5ec2c55a01977c37369
180 Risk Score

Malware Insights

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

The sample is an Excel 4.0 macro sheet that contains an Auto_Open macro, which is a known technique for executing malicious code upon opening the document. The document body mimics a prompt to "Enable Editing" and "Enable Content", further supporting the lure to execute the macro. The presence of dangerous formula APIs and environment evasion gates in the XLM macro indicates malicious intent.

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) 263397 bytes
SHA-256: fcbbfb6ba90c68222098789409c869e4ad866d2863674ca47d74020a2a8273d3
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     14 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  WOF1t
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open hidden len=7 ptgNameX  NAMEIDX 15 
' 0018     27 LABEL : Cell Value, String Constant - ffQLwGRTHNkr len=0 
' 0018     25 LABEL : Cell Value, String Constant - iPteKupKEu len=0 
' 0018     20 LABEL : Cell Value, String Constant - jbTKB len=0 
' 0018     25 LABEL : Cell Value, String Constant - JfvDYFRYTD len=0 
' 0018     26 LABEL : Cell Value, String Constant - LJBIRpkvgpf len=0 
' 0018     25 LABEL : Cell Value, String Constant - LOeTnZWstf len=0 
' 0018     21 LABEL : Cell Value, String Constant - qwOqnE len=0 
' 0018     25 LABEL : Cell Value, String Constant - RQzkQdwfJu len=0 
' 0018     25 LABEL : Cell Value, String Constant - rXSUVAwmlR len=0 
' 0018     27 LABEL : Cell Value, String Constant - sDtnuAulhodf len=0 
' 0018     23 LABEL : Cell Value, String Constant - SDuTgymL len=0 
' 0018     22 LABEL : Cell Value, String Constant - sXAggRK len=0 
' 0018     24 LABEL : Cell Value, String Constant - UKWCsUHGM len=0 
' 0018     28 LABEL : Cell Value, String Constant -        hidden len=7 ptgRef3d  Sheet!I12125 
' 0018     27 LABEL : Cell Value, String Constant - XjJzqHLEpBNW len=0 
' 0018     26 LABEL : Cell Value, String Constant - YMednwCsfTq 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
' 0
... (truncated)