Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 d5863a88daef812d…

MALICIOUS

Office (OLE)

255.5 KB Created: 2020-08-04 08:20:28 Authoring application: Microsoft Excel First seen: 2020-09-07
MD5: e83a14628fa16cfdf8be7938a2c7501d SHA-1: 37e2aa425c3c36d0a7d5417f702fff7d32828651 SHA-256: d5863a88daef812d3d5d317037abeb1a65d9669a9279f4986b8b52bfb25d292c
180 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.005 Visual Basic T1203 Exploitation for Client Execution

The sample is an Excel 4.0 macro-enabled workbook. Heuristics indicate the presence of an Auto_Open macro that uses dangerous functions and includes environment evasion. The document body attempts to lure the user into enabling editing and content, which would allow the macro to execute. No specific IOCs were extracted, but the presence of an Auto_Open macro strongly suggests 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) 267596 bytes
SHA-256: 2f0a6b4bc80f10c0427db852d4bb7041df5593f1fc1c6c4c7b652a6298c2cdfc
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     15 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  jY9Sk9
' 0018     27 LABEL : Cell Value, String Constant - AmSJMdWXKsqN len=0 
' 0018     21 LABEL : Cell Value, String Constant - aoZKDt len=0 
' 0018     26 LABEL : Cell Value, String Constant - aUFpwCqumZY len=0 
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open hidden len=7 ptgNameX  NAMEIDX 16 
' 0018     22 LABEL : Cell Value, String Constant - ekyDkhq len=0 
' 0018     24 LABEL : Cell Value, String Constant - ErJZOFzMX len=0 
' 0018     22 LABEL : Cell Value, String Constant - fnlQudS len=0 
' 0018     26 LABEL : Cell Value, String Constant - GBfuYHkVeJG len=0 
' 0018     24 LABEL : Cell Value, String Constant - iYmlzEVtP len=0 
' 0018     24 LABEL : Cell Value, String Constant - JUOZpJxBX len=0 
' 0018     27 LABEL : Cell Value, String Constant - LDlBVFbDZluG len=0 
' 0018     25 LABEL : Cell Value, String Constant - MdjbwFQJMk len=0 
' 0018     24 LABEL : Cell Value, String Constant - pkRmPZMXL len=0 
' 0018     21 LABEL : Cell Value, String Constant - RojDnt len=0 
' 0018     26 LABEL : Cell Value, String Constant - tibscznfFjh len=0 
' 0018     32 LABEL : Cell Value, String Constant -            hidden len=7 ptgRef3d  Sheet!HD11167 
' 0018     26 LABEL : Cell Value, String Constant - ZsYaJcFKweY 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

... (truncated)