Malicious PDF — malware analysis report

Static analysis result for SHA-256 2d09743345da21a5…

MALICIOUS

PDF

73.4 KB Created: 2021-09-15 19:28:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 99d7d35bd696ad86eb1e8145c5b68524 SHA-1: e3621e1d69a822e39aeb4a909922d084d35e0566 SHA-256: 2d09743345da21a5df788235750259f57fc55f11fed59c12bc5c7566e5848715
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or distributing further malware. No scripts were extracted, but the structure and URL patterns are indicative of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://heatexchangersolution.com/upload_fck/file/2021-9-4/20210904164853335219.pdf In PDF document text
    • https://huangs.tw/uploads/files/202109040004411045.pdfIn PDF document text
    • https://www.burit.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613ed86fd89a4---gujalomiki.pdfIn PDF document text
    • https://s-oil.hoakhanh.vn/uploads/image/files/5082885217.pdfIn PDF document text
    • http://netisiletisim.com/guvennet/resimlerfiles/fupalorulajizuwaguvime.pdfIn PDF document text
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/16131db2505b00---pagadawixo.pdfIn PDF document text
    • http://nacyc.jp/Upload/file/41565631964.pdfIn PDF document text
    • https://bfull.ru/uploads/files/59895542132.pdfIn PDF document text
    • https://viboot.traigiongthuha.com/ckfinder/userfiles/files/64829372042.pdfIn PDF document text
    • http://josepholszowka.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/dobujumobig.pdfIn PDF document text
    • http://enjoyisagenix.com/ckfinder/userfiles/files/vizajutulipajojanul.pdfIn PDF document text
    • http://www.danvillern.com/wp-content/plugins/super-forms/uploads/php/files/3750354a61ce41da70a3f01c48d7dc17/kasidotemojaf.pdfIn PDF document text
    • https://dunaweb.co/bg_image/files/milunuzeturozixigubaf.pdfIn PDF document text
    • http://www.diplomat2014.ru/ckfinder/userfiles/files/jirekogane.pdfIn PDF document text
    • http://chinhsuasolieu.com/media/files/dedikorafojab.pdfIn PDF document text
    • https://autoprofi.ua/userfiles/file/57831590803.pdfIn PDF document text
    • http://eternaseguros.net/files/files/39623653351.pdfIn PDF document text
    • http://blackhorsesc.pl/userfiles/file/wapebevi.pdfIn PDF document text
    • http://yogathoitrang.com/quangbasanpham/app/webroot/upload/image/files/30896399042.pdfIn PDF document text
    • http://behtarinekhodetbash.com/files/files/22368117229.pdfIn PDF document text
    • http://nenayu.com/filespath/files/20210905022408.pdfIn PDF document text
    • http://prodottoitalia.eu/userfiles/files/54628541641.pdfIn PDF document text
    • http://dlugopis.kbo.pl/ckfinder/userfiles/files/25600077831.pdfIn PDF document text
    • http://dream-mebel.com/pic/file/59945139602.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=a+positive+word+that+begins+with+the+letter+kPDF 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_off0000b8e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8E9 11036 bytes
SHA-256: 92a1910ebec296547babdf315ce093028df7b76f1e50f4e8a2c7fc6b24c826d4
font_01_sfnt_off0000d237.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD237 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ea49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA49 17452 bytes
SHA-256: acbdaca4e5c0147bee78b539e18a4f6f6b89bc6b570ec5ec24985ef3ec75bfc9