Malicious PDF — malware analysis report

Static analysis result for SHA-256 c680035fb788db39…

MALICIOUS

PDF

80.8 KB Created: 2021-09-23 18:44:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 6e82ba64cb7d026908d8298cd0cc39b5 SHA-1: 8f6fd9730e96a1f3f5acf5df961a59ff9de1b486 SHA-256: c680035fb788db39f4bd7637aba10b6e4e6536f07503335e80f43ae12a8264df
164 Risk Score

Malware Insights

MITRE ATT&CK
T1059.007 JavaScript T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, a common technique for executing malicious code or redirecting users. It also features a link farm pointing to multiple distinct hosts, some of which are identified as compromised CMS upload storage, suggesting an attempt to obscure the final malicious destination. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://bozoklar.org/ckfinder/userfiles/files/zunofivisokorebal.pdf In PDF document text
    • https://www.sudoku-cool.com/ckfinder/userfiles/files/62914871222.pdfIn PDF document text
    • http://gerocuki.hu/user/file/98227638019.pdfIn PDF document text
    • http://lalitas-thaimassage-spa.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614333e02fab4---55375018083.pdfIn PDF document text
    • https://ivanda-commerce.hr/userfiles/file/sewibis.pdfIn PDF document text
    • https://www.gs-gleichmann.de/wp-content/plugins/formcraft/file-upload/server/content/files/1614af6f9f239a---35992104399.pdfIn PDF document text
    • http://patronusalapitvany.hu/public_html/upload/lagekorezomasizerosazovi.pdfIn PDF document text
    • http://phutungototuanphat.com/img-tvdl/files/bevoxutazaduxutamanadigiv.pdfIn PDF document text
    • https://nnt52.ru/userfiles/file/2888329826.pdfIn PDF document text
    • https://aep-tc.com/cache/fck_files/file/xibosipanogonimekutenukil.pdfIn PDF document text
    • http://www.idukkidiocese.org/files/js/ckfinder/userfiles/files/28124777442.pdfIn PDF document text
    • https://seas2010.cienciaevida.pt/site/upload/file/87591872376.pdfIn PDF document text
    • http://zhongjiukeji.com/upload_fck/file/2021-9-5/20210905214935925186.pdfIn PDF document text
    • https://trungtammatnamviet.vn/upload/files/86421536166.pdfIn PDF document text
    • https://xn--fct5g39pjpo.tw/upload/leakstop/files/90982565736.pdfIn PDF document text
    • http://s4l.vn/storage/ckfinder/files/naruma.pdfIn PDF document text
    • http://orosweb.hu/ckfinder/userfiles/files/28695533452.pdfIn PDF document text
    • http://deurenhanger.nl/userfiles/file/gaxafabibeja.pdfIn PDF document text
    • http://ambcavallon.eu/userfiles/files/83700862416.pdfIn PDF document text
    • http://archgeo-leszno.pl/uploads/userfiles/files/nafotovipeluli.pdfIn PDF document text
    • https://lesrimaudieres.com/images/uploads/file/34408607569.pdfIn PDF document text
    • https://nwdglobal.com/ckfinder/userfiles/files/2643529624.pdfIn PDF document text
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140f097c1238---9216042590.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=tekken+5+psp+romPDF 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_off0000d715.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD715 18492 bytes
SHA-256: 31825d20a290ee08eb2d154fd440b48cbab42822f513fa3b78a0f6337af31be5
font_01_sfnt_off000106cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x106CD 10204 bytes
SHA-256: 0a44c42d4f405b664e421421b3812589fb54e9a575d34a9b128efb8e68a9c47f
font_02_sfnt_off00011db8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DB8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1