Malicious PDF — malware analysis report

Static analysis result for SHA-256 35c303bf7a09e852…

MALICIOUS

PDF

80.0 KB Created: 2021-10-04 21:14:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: c99591d2ffcd78c60cc7dfa7c8aa1c89 SHA-1: a0c1ed2d397dd7f616ded70e827f1c3e86411bf8 SHA-256: 35c303bf7a09e852d62704ca543b5626fd24431bd6fe81a5be718bf03a573bb4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm with numerous URLs pointing to other PDF files, many hosted on compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. While no scripts were directly extracted, the structure and URL patterns are consistent with malicious PDF lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://togelunited4d.com/contents/files/47330449501.pdf In PDF document text
    • http://triple-a.co.th/ckfinder/userfiles/files/kazox.pdfIn PDF document text
    • http://xn--franzsischebulldoggen-lec.eu/userfiles/file/75977155826.pdfIn PDF document text
    • https://www.tristar-technology.com/ckfinder/userfiles/files/62632385155.pdfIn PDF document text
    • https://chongtham68.com/app/webroot/uploads/files/55535513031.pdfIn PDF document text
    • http://giovanninociti.com/userfiles/files/69873207094.pdfIn PDF document text
    • http://bodegaadrover.com/userfiles/imagenes/73537505281.pdfIn PDF document text
    • http://tt-ural.su/admin/ckfinder/userfiles/files/79195433182.pdfIn PDF document text
    • http://nature-revive.org/files/file/4230192567.pdfIn PDF document text
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613a49e5baf32---fejevukurevejonup.pdfIn PDF document text
    • https://lajovisena.com/gallery/file/52328859824.pdfIn PDF document text
    • https://woodfur.in/userfiles/file/jasanuz.pdfIn PDF document text
    • http://telegid.tv/userfiles/files/55908601197.pdfIn PDF document text
    • http://simsvizag.com/contentimages/file/18805674994.pdfIn PDF document text
    • http://stigstudiotecnico.it/userfiles/files/38169076251.pdfIn PDF document text
    • http://kasintorn.com/images/upload/files/fubezogoki.pdfIn PDF document text
    • https://inchirieriavioane.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1614812e5806a2---96736654695.pdfIn PDF document text
    • https://www.taxikladis.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1615aab7fcefd2---44430522340.pdfIn PDF document text
    • http://naturallabs.fr/userfiles/file/magibuvezisiti.pdfIn PDF document text
    • http://ilink.pl/userfiles/file/61980390827.pdfIn PDF document text
    • http://turatabor.hu/media/pekapoxopi.pdfIn PDF document text
    • http://naphotelbangkok.com/userfiles/files/nebami.pdfIn PDF document text
    • http://bonsite.nl/phpcmsys/file/jitirukexede.pdfIn PDF document text
    • https://ebooksweb.net/files/file/reweboxulugi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=cesarean+section+in+cattlePDF 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_off0000d170.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD170 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e982.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE982 19484 bytes
SHA-256: c5203e8e816e15eff3982de3b31a9a950be6c6b9fa5114f1ddbdaa67b4ed711b
font_02_sfnt_off00011b2d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B2D 10252 bytes
SHA-256: 1ecb71a231997e2b1aa3195f84a68fa9ccbec33ed31d91254d873674101f29b9