Malicious PDF — malware analysis report

Static analysis result for SHA-256 25febf4db254a56a…

MALICIOUS

PDF

81.1 KB Created: 2021-09-16 19:35:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 3e82757f0978188a7330b3f9db456570 SHA-1: 143b5cd6b5cabe9f361dc75ab958abe15c90b866 SHA-256: 25febf4db254a56a8582348f98e5e6568ffc86eb33f0704b5d16b75d7206b7e5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to compromised CMS upload storage or disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and link farm nature are indicative of a phishing or malware distribution campaign, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://crysiq.ru/uplcv?utm_term=reels+views+apk PDF link annotation
    • https://laurallo.com/ckfinder/userfiles/files/26445025346.pdfIn PDF document text
    • https://giasidaily.com/uploads/userfiles/file/3331437477.pdfIn PDF document text
    • https://shiprapublication.com/uniformkontakt/userfiles/image/files/23833987948.pdfIn PDF document text
    • http://shbaicun.com/userfiles/file/2021090608225473499.pdfIn PDF document text
    • http://acunambalaj.com/adenoto/upload/files/xugizulureremazog.pdfIn PDF document text
    • https://vidaleve.net/ckfinder/userfiles/files/fixof.pdfIn PDF document text
    • http://prestinoequitacion.com/imagenes/upload/files/kimipuwakigu.pdfIn PDF document text
    • http://de.ruben.pl/ckfinder/userfiles/files/puburas.pdfIn PDF document text
    • http://www.expertnutritionadvisor.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130a86d9276c---faxubu.pdfIn PDF document text
    • https://guadix.co/ckfinder/userfiles/files/kalomezinazupuxe.pdfIn PDF document text
    • https://techson-cctv.com/upload/file/11770880387.pdfIn PDF document text
    • https://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/9ora9gmc2njkdui52kok3jmkkt/ganasawikafifizafujijazu.pdfIn PDF document text
    • https://vidaleve.net/ckfinder/userfiles/files/saloxilutaninetegikozoxul.pdfIn PDF document text
    • http://mobilenmr.com/files/files/nobejurixemubugajawo.pdfIn PDF document text
    • http://as-eng.biz/userfiles/file/51588901682.pdfIn PDF document text
    • https://khachsan295doson.vn/namthuan/images/news/files/kuxuter.pdfIn PDF document text
    • https://sagarexpress.com/userfiles/file/dududanewawoxovijefuvunax.pdfIn PDF document text
    • https://regenerateacademy.com/file/fuginexoginuwi.pdfIn PDF document text
    • http://dlabiura.kbo.pl/ckfinder/userfiles/files/85824615800.pdfIn PDF document text
    • http://happysmilecard.com/uploads/files/wazulijitigijufajexa.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16137ad9e78d70---36579649597.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161412c1b1a8e1---12179784122.pdfIn PDF document text
    • http://choragwica.pl/userfiles/file/tubozer.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_off0000d9b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9B3 10112 bytes
SHA-256: 5b1470c379adcc753b04c98ecea60884dd8f85a9b20110beb2565590cd35b5f2
font_01_sfnt_off0000f06c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF06C 17736 bytes
SHA-256: 5176c09ee547a3511a213da8bc31c3b3e844ace9336e3db9acc2c2d40b09029b
font_02_sfnt_off00011ec8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EC8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1