Malicious PDF — malware analysis report

Static analysis result for SHA-256 e73d36e072b3b0bb…

MALICIOUS

PDF

71.1 KB Created: 2021-09-20 07:17:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 20cd044efacf2c44da09d0b2d7129346 SHA-1: 9dfd03c7c5805e0a78ca57d175fe6cd45a2d4677 SHA-256: e73d36e072b3b0bbd2e9c788fd2192acf81d35c677e4bf15e7b8abf91103e708
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs pointing to a link farm, suggesting a phishing or SEO poisoning attack. The `PDF_SEO_DISPOSABLE_LINK_FARM` heuristic further supports this, indicating the PDF is part of a network of disposable hosting for link distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • 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://runhouchem.com/upload/files/ketizagikoripofekakivizo.pdf In PDF document text
    • https://tailormade-sales-marketing.com/userfiles/file/73497118180.pdfIn PDF document text
    • http://namuvaldymas.lt/userfiles/file/41880108203.pdfIn PDF document text
    • http://suachuadienlanhhoaphat.com/hinhanh_fckeditor/file/78723770735.pdfIn PDF document text
    • https://www.luthier-auxerre.fr/ckfinder/userfiles/files/98148604136.pdfIn PDF document text
    • https://99shayari.in/userfiles/files/rozubuzububebinidupoma.pdfIn PDF document text
    • http://jcnjl.com/userfiles/files/rijoletidit.pdfIn PDF document text
    • http://ideviceplus.be/app/webroot/files/userfiles/files/napiverorasojowa.pdfIn PDF document text
    • https://clubkdo.fr/img/pics/files/66117477417.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/0617210301609b541eaedf5e0c92eb44/jowibewuxuxuro.pdfIn PDF document text
    • https://dhesient.com/media/nodotimopilubetesowi.pdfIn PDF document text
    • https://thietkeweblongan.com/upload/files/31587440593.pdfIn PDF document text
    • http://stringladies.cz/userfiles/68719212061.pdfIn PDF document text
    • https://habibitours.com/ckfinder/userfiles/files/zejesapiregukibi.pdfIn PDF document text
    • https://www.kadinlarsitesi.org/wp-content/plugins/formcraft/file-upload/server/content/files/161442d6aeecc3---medatasamel.pdfIn PDF document text
    • http://inter-travel.hu/_user/file/wanotadulakir.pdfIn PDF document text
    • https://deltarents.com/upload/ckfinder/files/27045901496.pdfIn PDF document text
    • http://tandartsindex.nl/images/uploads/19151852371.pdfIn PDF document text
    • http://tydafa.com/dafa/uploadfiles/20210911145050.pdfIn PDF document text
    • http://matonaklawfirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/jununulutokalekuviginixat.pdfIn PDF document text
    • https://korovin.org/site/img_ufiles/sexufikadowenabage.pdfIn PDF document text
    • http://netmutum.com/userfiles/file/7390909012.pdfIn PDF document text
    • https://sergiomauri.com/images/file/99655064666.pdfIn PDF document text
    • https://maytinhdalat.vn/images/uploads/files/12805233411.pdfIn PDF document text
    • http://tochalco.com/uploads/files/wagulujevomitomeme.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=fahrenheit+451+figurative+language+pdfPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b607.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB607 15812 bytes
SHA-256: 2cdcccfad33ea6713381838138f6d6f9b75114f09d3546cd30de9e9a5cfe2ecc
font_01_sfnt_off0000dd99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD99 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f5b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5B0 10896 bytes
SHA-256: 1245ce73f34a9d41d0ebd34c1e8013a6a6a7243a2c1f09144f0f7d6f3d373263