Malicious PDF — malware analysis report

Static analysis result for SHA-256 f1a35db1213f930a…

MALICIOUS

PDF

76.7 KB Created: 2021-09-05 15:46:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 3d96c6ba02e36d4663b89002c06b2e59 SHA-1: cc234dfc6def0c8de3686597a9564b60e1d9b86e SHA-256: f1a35db1213f930ad5d36ac67c6995bf8c58d8cca21c4cdb763196cb6b2e5ef9
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many pointing to compromised WordPress sites and disposable domains, suggesting a link farm for SEO manipulation or phishing. ClamAV detected this file as Pdf.Phishing.Trojan, and the ML classifier also flagged it as malicious with high confidence. No scripts were extracted, but the presence of multiple malicious URLs indicates a clear intent to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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://laborke.ru/uplcv?utm_term=theory+and+methods+of+survey+sampling+by+parimal+mukhopadhyay+pdf PDF link annotation
    • https://bodwellassociates.com/wp-content/plugins/super-forms/uploads/php/files/c61e4df56c82dae47192b2d39ab2403c/dokok.pdfIn PDF document text
    • http://toptoptraining.ru/img/upload/file/wikolemibivoluvuzesap.pdfIn PDF document text
    • https://akapacha.com/userfiles/file/musodokuxifakebivijamit.pdfIn PDF document text
    • http://aucoindeshalles.com/menu/file/vugixek.pdfIn PDF document text
    • https://questyme.com/userfiles/file/nazimimenaburexasib.pdfIn PDF document text
    • http://museodegliarazzimarsala.com/userfiles/files/77702084835.pdfIn PDF document text
    • https://www.advids.io/wp-content/plugins/formcraft/file-upload/server/content/files/1607bdd47ec7ee---21845626597.pdfIn PDF document text
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/160ce5948634f8---vupepurezibawiligilixu.pdfIn PDF document text
    • http://www.tokyomagic.jp/images/library/File/53170339827.pdfIn PDF document text
    • http://designbeginnings.com/upload/file/lemekabupinof.pdfIn PDF document text
    • https://takipcisec.com/calisma2/files/uploads/15358763471.pdfIn PDF document text
    • http://furkansigorta.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1612c46a8ec6fe---waxifojo.pdfIn PDF document text
    • http://nousgarage.com/userfiles/file/80448805234.pdfIn PDF document text
    • http://we2meeting.com/ckfinder/userfiles/publics/files/pokag.pdfIn PDF document text
    • http://apluskleaning.com/admin/images/file/tonamebezij.pdfIn PDF document text
    • https://cbolean.com/wp-content/plugins/super-forms/uploads/php/files/vc5nj2i3l48vor0nkjm22hata0/xataraj.pdfIn PDF document text
    • http://baltic-rt.ru/ckfinder/userfiles/files/25285738529.pdfIn PDF document text
    • https://mithermomix.com.mx/wp-content/plugins/super-forms/uploads/php/files/40ac2c09eaae04d2424b059441105beb/zuzivimukitulinosunutetag.pdfIn PDF document text
    • http://maxidmum.com/images/upload/fck/file/73698548183.pdfIn PDF document text
    • https://saintarseny.ca/sites/saintarseny.ca/files/file/tepunejajelikomele.pdfIn PDF document text
    • https://www.cfo-search.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b5e66c906ff---21341691298.pdfIn PDF document text
    • https://francoisdaulte.com/ckfinder/userfiles/files/menuxedejojuvotefof.pdfIn PDF document text
    • https://asiajitutop.com/contents//files/95169818642.pdfIn PDF document text
    • https://loctra.net/userfiles/file/zafodaw.pdfIn PDF document text
    • http://hoaiduc.edu.vn/ckfinder/userfiles/files/risubudemivajixeve.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_off0000c875.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC875 11420 bytes
SHA-256: 66d899d9403ecc15a48d3bfef30736e3a1955d035d64db74657a3d64e3547366
font_01_sfnt_off0000e2d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2D4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fae6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAE6 16344 bytes
SHA-256: 4d1b47ffea77130b203762c0be29d84155954e12a2b037539fd9ea067b4f3aa1