Malicious PDF — malware analysis report

Static analysis result for SHA-256 efbd9132f8a73b67…

MALICIOUS

PDF

123.8 KB Created: 2021-07-13 07:22:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: c8b77efe50da14a8cb24235c424025c0 SHA-1: b2d31b4fe26f5f698c9991860fce495cb87a1a91 SHA-256: efbd9132f8a73b67faa92272fc05f47b50fb528aadb420a27933202bf6fec2f9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by multiple heuristics as a link farm, with many URLs pointing to compromised CMS upload directories. The ML classifier and ClamAV also identified it as malicious, specifically as a phishing trojan. The document body is unreadable, but the presence of numerous external links suggests a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9928

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://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606d63ffaf35d---lazokatizimasi.pdf In PDF document text
    • http://sparan-art.ru/ckfinder/userfiles/files/xazewofoxajorapavinibunag.pdfIn PDF document text
    • https://fieldofgreen.com/wp-content/plugins/super-forms/uploads/php/files/eeba53e9ececec22b1424132b6263724/kigenotatatafo.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/o2380hqpeqbci8h8j8ln4e2mvu/ranekulusa.pdfIn PDF document text
    • https://glowskincare.net/wp-content/plugins/super-forms/uploads/php/files/a28b1174c962af0932ddeae34cf4d705/38425926544.pdfIn PDF document text
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160939fd7cf5ef---mokamutikazit.pdfIn PDF document text
    • http://markfarolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/rozajutisapod.pdfIn PDF document text
    • https://miet.hu/kepek/72421120569.pdfIn PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/160994be6af15e---xilava.pdfIn PDF document text
    • http://hoondb.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076a6540bf1e---86724065242.pdfIn PDF document text
    • https://www.getfitcrew.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083283aefab5---zodixuvisosefotosox.pdfIn PDF document text
    • https://qnzar.com/files/femoba.pdfIn PDF document text
    • http://in-dapt.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d3ce2852de---33020043901.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609da2c3b2501---tewunageperexisane.pdfIn PDF document text
    • http://agiusfuneraldirectors.com/files/file/96719826685.pdfIn PDF document text
    • http://sakirnoopo.ru/wp-content/plugins/super-forms/uploads/php/files/d4c0c4e9a973ad4bf8e32606e0424bcf/sudowepagovuzekal.pdfIn PDF document text
    • http://xoblates.com/clients/e/e0/e08cfb93fb97b00c28394d0532709dc9/File/sudeva.pdfIn PDF document text
    • http://www.onlinetemsilci.com/wp-content/plugins/formcraft/file-upload/server/content/files/160821bf1b785e---xopuluwe.pdfIn PDF document text
    • https://kassa-evotor.ru/wp-content/plugins/super-forms/uploads/php/files/a8cssnfpcbofgtc65fr3ohog3g/64231282124.pdfIn PDF document text
    • https://reazfarah.com/ckfinder/userfiles/files/40660928282.pdfIn PDF document text
    • http://guides2alpes.fr/uploads/file/misowanidopu.pdfIn PDF document text
    • https://cananalimdar.com/wp-content/plugins/super-forms/uploads/php/files/brf3al45g9g90sc8l4bn5b1v18/31150211093.pdfIn PDF document text
    • https://stopserv.ru/files/file/damubakuvag.pdfIn PDF document text
    • https://rosemonttherapy.health/wp-content/plugins/super-forms/uploads/php/files/euj68tfmto6gp5e4t0ljoltj5b/pojudoxikixupetebax.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=reformed+anglican+churchPDF 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_off00018473.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18473 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00019c8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x19C8A 10800 bytes
SHA-256: 106b3b13013cced36e039da28623ea2a4a64aa96efd3443c62783302e7a8f03b
font_02_sfnt_off0001b4f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1B4F1 17600 bytes
SHA-256: dcc99e7a7c0c1a63758405c71ec74da2efb22becc65a90f3ec17e74eed5d4b99