Malicious PDF — malware analysis report

Static analysis result for SHA-256 857f22af867ef734…

MALICIOUS

PDF

70.8 KB Created: 2021-09-26 01:05:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: dce6612174f7ac0186f0af8e4f189eb8 SHA-1: 985757d1b9d5f6231cb2592ebd7e63a7b313cc90 SHA-256: 857f22af867ef7349e3de47950a2ac60280773d9e205f43f32082cb2330c0ac8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised WordPress upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious content. While no scripts were explicitly extracted, the nature of the links and the 'link farm' heuristic indicate an attempt to exploit user interaction for malicious purposes.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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 http://rsentco.com/upload/file/19026278504.pdf In PDF document text
    • http://www.cuadernos.in/wp-content/plugins/formcraft/file-upload/server/content/files/16132a64aaf804---tukewowumelaniluginuf.pdfIn PDF document text
    • https://irrisyst.eu/files/file/7515349223.pdfIn PDF document text
    • https://neurondevelopment.org/userfiles/file/leruzid.pdfIn PDF document text
    • https://laplacedesstores.com/upload/file/kinenojawisotelubotegu.pdfIn PDF document text
    • http://at2apigroup3.com/contents/files/54794834327.pdfIn PDF document text
    • https://mycocoa.org/images/upload/files/7504117566.pdfIn PDF document text
    • http://hongdanhaudio.com/luutru/files/xabomamofawakevokog.pdfIn PDF document text
    • https://georeno.ca/userfiles/files/2945464864.pdfIn PDF document text
    • http://xn--76-6kca8aqc6c.xn--p1ai/pic/userfile/zukuribarus.pdfIn PDF document text
    • http://www.romanschatztruhe.de/img/files/bilodukuzupafigi.pdfIn PDF document text
    • http://lightningriskassessment.com/ci/userfiles/files/60338908429.pdfIn PDF document text
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142e8a9db7d7---wunafuvunude.pdfIn PDF document text
    • http://fajni3333.fun4two.pl/uploads/assets/file/70580697966.pdfIn PDF document text
    • https://mongolia-volkslift.com/uploads/files/budojanonuvojizijajituxi.pdfIn PDF document text
    • https://gopherscopes.com/userfiles/file/mamazewaxoduwi.pdfIn PDF document text
    • https://monarchwinemerchants.com/wp-content/plugins/super-forms/uploads/php/files/6f1e46e5006c706d1fc5b2a2aa42c589/35856000681.pdfIn PDF document text
    • http://slesnick.net/userfiles/files/61293813868.pdfIn PDF document text
    • https://ibshospitals.com/userfiles/file/wuwol.pdfIn PDF document text
    • http://ukrfirework.com/images/file/8943598534.pdfIn PDF document text
    • http://hiroi-es.info/yamituki-n/uploads/files/23292509391.pdfIn PDF document text
    • http://www.offshoreyachts.net/web_upload/editor/files/58427396603.pdfIn PDF document text
    • http://dsagco.com/Upload/file/kelivafuv.pdfIn PDF document text
    • http://liga-stf.ru/i/upload/files/monivufimafiraluxe.pdfIn PDF document text
    • http://tokyoracing.hu/userfiles/file/56569395659.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=how+are+prokaryotes+and+eukaryotes+the+samePDF 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_off0000b239.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB239 10904 bytes
SHA-256: 0512e145e5a6f2761f86aee60b1d8c944622f816ea3763ef8cf54d10d8becbe5
font_01_sfnt_off0000cb53.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB53 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e365.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE365 16532 bytes
SHA-256: 25d0d69c423aafd033575aec7880873c2de18bbca80179cee814d82001d44738