Malicious PDF — malware analysis report

Static analysis result for SHA-256 88d7710dd8b4afc4…

MALICIOUS

PDF

87.6 KB Created: 2021-07-05 14:20:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 7b2fb24f151d511890b0dc8cac7c60b4 SHA-1: fe9488d122ff3708a582346a78da4524d791f456 SHA-256: 88d7710dd8b4afc46a932b884b939c42a5c03cb4a9052ad15b73239add3ac20b
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to compromised WordPress sites, which in turn host other PDF files. This suggests a link farm designed to distribute malicious content, likely for phishing or malware delivery. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://ketchas.ru/uplcv?utm_term=the+ultimate+guide+to+body+recomposition+book+pdf PDF link annotation
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e34d26a604---87693108504.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160b2c82040d5e---bufabovegi.pdfIn PDF document text
    • http://sieckultury.pl/wp-content/plugins/super-forms/uploads/php/files/a69284e9194771e1c74eb814bcd7c362/34775304863.pdfIn PDF document text
    • http://harekatmemuru.com/images/Media/files/sujovumelumofomonovature.pdfIn PDF document text
    • https://paklya.su/design/img/upload/file/nidugapodezadezabarud.pdfIn PDF document text
    • http://musorcentrum.hu/files/article/file/gedolaravumoxamok.pdfIn PDF document text
    • http://botanicgardenscafe.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16084f5c9899f5---xomujirujukuginajatovu.pdfIn PDF document text
    • https://www.nosolodespedidas.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608bcbb1216eb---49185806092.pdfIn PDF document text
    • https://bushregenerators.biz/userfiles/files/92490466368.pdfIn PDF document text
    • https://etadelloro.it/images/file/zogefavodud.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/6a2eeaebdde84a5f816b60512cab2678/55961551299.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/63098501175.pdfIn PDF document text
    • https://etre-cheval.fr/Applications/MAMP/htdocs/etre%20cheval/news_pix/file/sefudaxadokozesukazix.pdfIn PDF document text
    • https://messianic.live/wp-content/plugins/super-forms/uploads/php/files/f456838dac6eb43f36e2086634126079/4961130099.pdfIn PDF document text
    • http://1utilaje.ro/mm/file/sidud.pdfIn PDF document text
    • http://erdivigado.hu/userkepek/file/85453124198.pdfIn PDF document text
    • https://ijpdua.com/contents//files/zakigizuwosudaguz.pdfIn PDF document text
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b12ca9bb074---visulupuvis.pdfIn PDF document text
    • http://fine-cottage.ru/userfiles/file/viderilipijikabewilejulib.pdfIn PDF document text
    • http://ufnk.fr/app/webroot/files/file/wuret.pdfIn PDF document text
    • http://serendipityorlando.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cbc65edcade---72338653273.pdfIn PDF document text
    • http://pizzeria-millemiglia.de/app/webroot/img/editor/file/mujoz.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_off0000f1c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1C4 17172 bytes
SHA-256: d1911cc657acf1f830d834aa70921eb2f4590b3f95458a918666d11cf88571d7
font_01_sfnt_off00011e7e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E7E 11476 bytes
SHA-256: 690de363fd17777a8a8df4ab894bfe406df6baedb7d8ed0ddac10b26f0b8fc27
font_02_sfnt_off00013903.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13903 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1