Malicious Office (OLE) / .XLSX — malware analysis report

Static analysis result for SHA-256 73fc795d2700a577…

MALICIOUS

Office (OLE) / .XLSX

142.0 KB Created: 2015-06-05 18:17:20 Authoring application: Microsoft Excel
MD5: 4de17e78f8af5749d8ce450b9961b3eb SHA-1: f0c7039c293e5edaa20781944d5bf4a2af2fa14e SHA-256: 73fc795d2700a577c4b412289e40662ac6541fe4ba64e2e4af2b259f15f534f8
302 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1566.001 Spearphishing Attachment T1105 Ingress Tool Transfer

The sample contains VBA macros, including a Workbook_Open event, which is a common technique for executing malicious code upon opening. The macros attempt to reconstruct and execute a command that downloads and runs a batch file from one of the provided URLs. This indicates the primary purpose is to act as a downloader for further malicious payloads.

Heuristics 8

  • URL reconstructed from VBA cell-staged base64 dropper (11 URLs) critical OLE_VBA_CELL_DROPPER_URL
    VBA reads worksheet cells, strips junk substrings via Replace(), and base64/UTF-16 decodes the result into a PowerShell EncodedCommand payload. The download URL is never contiguous in the file bytes; it was recovered by removing the macro's Replace() junk tokens from the cell strings and decoding the staged base64.
  • ClamAV: Doc.Malware.Valyria-10004384-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Malware.Valyria-10004384-0
  • Reference to Windows Script Host high SC_STR_WSCRIPT
    Reference to Windows Script Host
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • VBA macros detected medium OLE_VBA_MACROS
    Document contains VBA macro code
  • 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://goyaluat.vmesh.in/0v6kcny/CG/
    • https://mars.srl/wp-admin/7Ffk6LLN2Xs2W/
    • http://franmulero.es/mbx/8c5RBJx6/
    • http://varafood.com/Ajax/cnM91G/
    • https://7jcat.com/wp-content/t/
    • http://blog.centralhome.h
    • http://zimrights.co.zw/oldsite/k0EoCWycU9tNo1d/
    • https://mudhands.com/error/BfH/
    • http://albatrospatagonia.com/phkcvt/t53ceSMDqgPQlq/
    • http://mapcommunications.co.zw/wp-admin/mdRRbSdU3aB7Xpx6z/
    • http://dushkin.net/img/bhQSTNicEMtNQxP/

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
527d0656a0c2c323955d068683ef8f7e20c035cda247a1e24383595c0eb3403b
vba-macro oletools.olevba.extract_macros (decoded VBA source) 7821 bytes