Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 de8f0c10345af57a…

MALICIOUS

Office (OLE)

292.5 KB Created: 2020-07-10 10:41:45 Authoring application: Microsoft Excel First seen: 2020-09-15
MD5: c57ccc71cc25b2bfd3068264e639f94f SHA-1: 2712b0cef74d9e365cab0b3074f90b6333245105 SHA-256: de8f0c10345af57a06a9f5a64f7fe2916e96b02f16c6bbb10fbc11325eebc3f8
242 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 that uses an Auto_Open macro to execute. Heuristics indicate a lure to enable macros and impersonation of a document signing service. ClamAV detection confirms it is a known dropper family. The XLM macro sheet contains dangerous functions like RUN, suggesting it is designed to download and execute a second-stage payload.

Heuristics 7

  • ClamAV: Xls.Dropper.Agent-8840686-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Dropper.Agent-8840686-0
  • 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.
  • 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
  • Document signing service impersonation lure medium SE_DOCUSIGN_LURE
    Document impersonates DocuSign, Adobe Sign, or a similar signing service in a signing-request context
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://www.w3.org/1999/02/22-rdf-syntax-ns# In document text (OLE body)
    • http://ns.adobe.com/xap/1.0/mm/In document text (OLE body)
    • http://ns.adobe.com/xap/1.0/sType/ResourceRef#In document text (OLE body)
    • http://ns.adobe.com/xap/1.0/In document text (OLE body)

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) 51739 bytes
SHA-256: 1c81be3cb0232f7c7ccae9086d59fc477f0172329312024ee5c163d9e3580829
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, very hidden -  Sheet
' 0085     11 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  QM
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  Sheet
' 0085     17 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, hidden -  EcVRctId
' 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     23 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open len=7 ptgRef3d  Sheet!T5952 
' 0018     29 LABEL : Cell Value, String Constant - HoGrvWKHBTQnJh len=0 
' 0018     23 LABEL : Cell Value, String Constant - JReGZFdu len=0 
' 0018     25 LABEL : Cell Value, String Constant - njv len=7 ptgRef3d  Sheet!FJ50507 
' 0018     23 LABEL : Cell Value, String Constant - pYvfpvrE len=0 
' 0018     23 LABEL : Cell Value, String Constant - uwcjDLzf len=0 
' 0018     27 LABEL : Cell Value, String Constant - VMCQaJJviKgs len=0 
' 0018     23 LABEL : Cell Value, String Constant - YWbMTaqS len=0 
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 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
... (truncated)