Malicious PDF — malware analysis report

Static analysis result for SHA-256 37910c3db3bc30c3…

MALICIOUS

PDF

109.8 KB Created: 2021-08-20 05:42:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 6b11d94a5d634b59567b203c05468bc3 SHA-1: c0866fdea3dabe04bbddc65f36d505e5aa9a3947 SHA-256: 37910c3db3bc30c33ef8f71a945bc4e42457b077f4569e2ab0b07b4a78d09472
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It contains numerous links, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of external URIs and link farm heuristics indicates an attempt to lead users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://www.kindspring.org/inc/ckfinder/userfiles/files/37789796678.pdf In PDF document text
    • https://ruh-center.ru/userfiles/file/96808983026.pdfIn PDF document text
    • http://beerskiboot.com/img/upload/file/45700980696.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f07c382ab71---40376267420.pdfIn PDF document text
    • http://somersetcountybar.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/xomarevuxudebunukonewewa.pdfIn PDF document text
    • https://diphong.com/uploads/12859286533.pdfIn PDF document text
    • http://www.seminariomenorvalencia.com/admin/lib/ckfinder/userfiles/files/sakovumevoxasoru.pdfIn PDF document text
    • https://palet-school.com/files/files/vitugerogadu.pdfIn PDF document text
    • https://www.paparazzirestaurant.com.au/wp-content/plugins/super-forms/uploads/php/files/0a92fb9f7cf0eb423f6a0a48365a240d/59667296420.pdfIn PDF document text
    • http://ulv-fogger.ru/d/files/29184467764.pdfIn PDF document text
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/27c24577d4529bce5f6af7282ecaa4ce/65516046098.pdfIn PDF document text
    • http://skncn.com/u/files/32357239672.pdfIn PDF document text
    • http://galerie45.com/userfiles/file/fekuve.pdfIn PDF document text
    • http://ebrinteractive.com/userfiles/file/71656513598.pdfIn PDF document text
    • https://rcot.org/userfiles/file/sobepisilosewezo.pdfIn PDF document text
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607754d02ed3f---girotezevonuginuwej.pdfIn PDF document text
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092eb69748d2---43330146985.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/mos7oeq5canojm31hteb1q9lf4/sewazejuvumazi.pdfIn PDF document text
    • http://luchetti.it/userfiles/files/japod.pdfIn PDF document text
    • https://itchanoi.vn/uploads/news_file/kapizudumuvilokumomavub.pdfIn PDF document text
    • http://globalnetworks.de/www.galabau-poscher.de/main/preview/ckfinder/userfiles/files/66419120073.pdfIn PDF document text
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607acb8a7376e---11989495646.pdfIn PDF document text
    • http://esejsc.com/upload/files/kabufuvatuvujofuvutuxoz.pdfIn PDF document text
    • http://albatrossmrn.com/konadnew/userfiles/file/50090433359.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607cc7524be89---6024344975.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=age+of+empires+3+definitive+edition+british+guidePDF 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_off0001482a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1482A 17660 bytes
SHA-256: 332b558761b3fa18cb4f80ac6fa97a1c19e18623f79f37720f6ea5ce2fda8ff2
font_01_sfnt_off000176cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x176CD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00018ee4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18EE4 11196 bytes
SHA-256: eade615cecfe3831dec7142096c60bf0eab1484a909ca960fa2b5c50d0c8086f