Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b9bc0b9fe2aa74a…

MALICIOUS

PDF

82.1 KB Created: 2021-09-18 16:10:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 14ca1b380d19b93d96150ea9d1526856 SHA-1: 45c53eebc8a7d5694dd0254642800823d1f7d028 SHA-256: 5b9bc0b9fe2aa74a30d040835ed47e349e23c6913558ee729023d293eb21528b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to compromised CMS upload directories, suggesting it's part of a link farm designed to redirect users. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this, indicating the PDF's primary function is to host and distribute links to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://allytemp.ru/uplcv?utm_term=medieval+japan+feudal+system PDF link annotation
    • https://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/6c4c1aba24dd3443d1b66c47bfc6c324/44888193585.pdfIn PDF document text
    • https://www.dekleinewerf.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161354003c25a6---wivisuwavinedozoni.pdfIn PDF document text
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613c66fa8a112---rafowaxegabixidulo.pdfIn PDF document text
    • https://digireg.cn/upload/zizafaganovafo.pdfIn PDF document text
    • http://szerecsen.hu/editor_up/petufebak.pdfIn PDF document text
    • https://polandpools.com/contents/files/nawajenuzozamuzubexuw.pdfIn PDF document text
    • http://foto-preiss.at/upload_files/files/72212968783.pdfIn PDF document text
    • https://lmetinternationalschool.in/ckeditor/ckfinder/userfiles/files/tazusubozupitus.pdfIn PDF document text
    • http://bloemenwinkelindex.nl/images/uploads/lalipusofomegu.pdfIn PDF document text
    • https://hagabb.ro/ckfinder/userfiles/files/vewodavoperezesun.pdfIn PDF document text
    • https://mcq.bmtinhoc.vn/InteriorWeb/images/images_news/files/2328729023.pdfIn PDF document text
    • http://pegastelco.com/pictures/files/mexanulejunazexaki.pdfIn PDF document text
    • https://hyundainhapkhau.vn/upload/files/65934566549.pdfIn PDF document text
    • https://ajansnigde.com/resimler/files/vapomuwir.pdfIn PDF document text
    • http://nanopena.cz/upload/file/63946483324.pdfIn PDF document text
    • https://hinodanang.com/uploads/image/files/50916393844.pdfIn PDF document text
    • http://magiepourenfants.com/images/mediamanager/file/baduvasenaxod.pdfIn PDF document text
    • https://dusunceokulu.net/resimler/files/44354579837.pdfIn PDF document text
    • http://mehmetrasimmutlu.com/icerik/file/79636561495.pdfIn PDF document text
    • http://begemot-rus.com/uploadfiles/file/2021090704590173499.pdfIn PDF document text
    • http://phdpecs.hu/userfiles/files/18000914482.pdfIn PDF document text
    • 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_off0000dbde.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBDE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f3f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3F0 17872 bytes
SHA-256: 58750ce63058c6bf1dbc278138147029717de9433a672e9c23dcbc7543f0aa5c
font_02_sfnt_off0001226a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1226A 10844 bytes
SHA-256: 910ff20bf228b994f59231cc80653289aa44bb74f67974a503648a2cc7984f28