Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 c3239e1334cf8e31…

MALICIOUS

Office (OLE)

36.0 KB Created: 2020-11-27 11:40:21 Authoring application: Microsoft Excel First seen: 2021-06-28
MD5: c3951a61d34ea23f080f26f5721b36eb SHA-1: 0c01dd9c7fd97918f4fcff5863bec22adef6e8d8 SHA-256: c3239e1334cf8e318e00d3503262c230c9774c4f3b58eefc2268d0a2ba291b1f
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The file contains Excel 4.0 macros, specifically an Auto_Open defined name, which is a critical finding indicating automatic execution upon opening. The presence of dangerous formula APIs like RUN suggests the macro is designed to execute arbitrary code, likely a downloader for a secondary payload. No specific family could be identified from the available evidence.

Heuristics 3

  • 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.
  • 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) 6707 bytes
SHA-256: 81233c5af0cfaa7ab65467bc779e0a5f53736a857b691a98d4ec807cbb8906d2
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     17 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  sKbCoMni
' 0018     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!C160 
' 0018     20 LABEL : Cell Value, String Constant - BvGRO len=0 
' 0018     20 LABEL : Cell Value, String Constant - dMtNb len=0 
' 0018     24 LABEL : Cell Value, String Constant - EbfiEmYzS len=0 
' 0018     23 LABEL : Cell Value, String Constant - EgmRSGas len=0 
' 0018     26 LABEL : Cell Value, String Constant - eQgoJXBovAr len=0 
' 0018     24 LABEL : Cell Value, String Constant - IGzvfKIAS len=0 
' 0018     26 LABEL : Cell Value, String Constant - JFQCwXLtuFI len=0 
' 0018     24 LABEL : Cell Value, String Constant - jQYtxpLNg len=0 
' 0018     25 LABEL : Cell Value, String Constant - kjDRohOcmg len=0 
' 0018     23 LABEL : Cell Value, String Constant - loYGfhwy len=0 
' 0018     22 LABEL : Cell Value, String Constant - LRlmJJV len=0 
' 0018     24 LABEL : Cell Value, String Constant - oJzCMxZNQ len=0 
' 0018     27 LABEL : Cell Value, String Constant - QAXtLUFxovrZ len=0 
' 0018     20 LABEL : Cell Value, String Constant - SsdUd len=0 
' 0018     20 LABEL : Cell Value, String Constant - SxSsK len=0 
' 0018     24 LABEL : Cell Value, String Constant - TJDqmDzyw len=0 
' 0018     21 LABEL : Cell Value, String Constant - UmFHTb len=0 
' 0018     23 LABEL : Cell Value, String Constant - wFCUCkqV len=0 
' 0018     22 LABEL : Cell Value, String Constant - WXxXvDO len=0 
' 0018     21 LABEL : Cell Value, String Constant - yNEZAu 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 LABEL
... (truncated)

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