Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca7c828af373467f…

MALICIOUS

PDF

82.2 KB Created: 2021-09-18 10:05:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 7da4e63bcd82ef817d8a5fcfd60beebc SHA-1: 4fa63ddefa9c73c86e47c54c022d2623aab500da SHA-256: ca7c828af373467fb4c48bb2b03389cfa2a5cec7120a27cca75420f1b697b58c
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm or SEO poisoning tactic. The ML classifier strongly indicated maliciousness, and the PDF structure with multiple external links aligns with techniques used to distribute malware or redirect users to phishing sites. No scripts were extracted, but the overall pattern of link distribution is suspicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • 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://irlanc.ru/uplcv?utm_term=free+pokecoins+ios PDF link annotation
    • http://arcstema.com/userfiles/files/jotorinof.pdfIn PDF document text
    • http://www.introspekta.si/ckfinder/ckeditor_uploaded_files/files/pujamax.pdfIn PDF document text
    • https://stancijanegrin.com/userfiles/file/28833275280.pdfIn PDF document text
    • https://iringmalaysia.com/ckfinder/userfiles/files/95764465005.pdfIn PDF document text
    • http://hockjoohin.com/admin/uploads/file/24753563364.pdfIn PDF document text
    • https://sofahatinh.com/upload/files/22801289241.pdfIn PDF document text
    • https://km2804.com/ckupload/files/14641079998.pdfIn PDF document text
    • https://speculatio.in/ci/userfiles/files/83237099847.pdfIn PDF document text
    • http://disonde.com/filespath/files/20210912104844.pdfIn PDF document text
    • https://bomnuocebara.com/quangbasanpham/app/webroot/upload/image/files/watajusuniguwala.pdfIn PDF document text
    • https://mobisteelegypt.net/userfiles/file/xurozamanolekotuwukab.pdfIn PDF document text
    • https://cvenhancer.com/wp-content/plugins/super-forms/uploads/php/files/ea0ccfe67008f9939cf7b3f200e88086/sejagijowuji.pdfIn PDF document text
    • http://realcomfort.ru/content/upload/file/39245777277.pdfIn PDF document text
    • http://cicm2015.mist.ac.bd/app/webroot/ckfinder/userfiles/files/pufetititikefi.pdfIn PDF document text
    • https://worldcastlive.com/userfiles/file/26849660343.pdfIn PDF document text
    • http://wyadonline.com/userfiles/file/3816001400.pdfIn PDF document text
    • http://89928386.com/uploads/files/202109130847245374.pdfIn PDF document text
    • https://mantyobras.com/userfiles/file/suvupusulixukitonenaxezik.pdfIn PDF document text
    • https://die-elke.de/cms/elke_page_files/file/7473074472.pdfIn PDF document text
    • https://rafautama.com/uploads/file/pepekiz.pdfIn PDF document text
    • http://rasmesafar.net/basefile/basefiles/28926995143.pdfIn PDF document text
    • https://fitnessrev.net/wp-content/plugins/super-forms/uploads/php/files/71eor6i3gb8ckkr21511t98d2n/81185140343.pdfIn PDF document text
    • https://dragonexpressml.com/userfiles/files/15466680175.pdfIn PDF document text
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/1614076ed0132b---33139553823.pdfIn PDF document text
    • http://joshuadacosta.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614275e06e024---72054514806.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_off0000d3a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3A8 21268 bytes
SHA-256: eba44c7c7f3ef674538ae150fab8d3181fb4f55237ce0b7eb9babd14e144b72b
font_01_sfnt_off00010c47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C47 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001245e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1245E 10132 bytes
SHA-256: a5b81088fedea73df06a08f55aa665bc38590f9db34601559dd437912e80c48d