Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef6ba24a4077f962…

MALICIOUS

PDF

68.1 KB Created: 2021-09-29 03:02:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 2037186616d242ca577dc55db591ddaf SHA-1: 6316f91c8e35e7511852331bced5a8dd27c0bde3 SHA-256: ef6ba24a4077f962241fb32b499d3b22282a3c0830c43d7e7aace579ae74dc8e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. Although no scripts were directly extracted, the PDF structure and embedded links are consistent with techniques used to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

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://crewmak.ru/uplcv?utm_term=voice+changer+apk+for+pubg PDF link annotation
    • http://midesignvn.com/uploads/files/buxavufepul.pdfIn PDF document text
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/16137d20d78532---wobajibukiz.pdfIn PDF document text
    • https://synersys.fr/contenu/file/73060333716.pdfIn PDF document text
    • https://soosekszer.hu/upload/files/fomedosalitivi.pdfIn PDF document text
    • http://www.tsssport.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614f0de597dd0---nirefuwiraxovekivoborelak.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138e936959f5---62521806523.pdfIn PDF document text
    • http://eis-pieschel.de/UserFiles/File/80072303509.pdfIn PDF document text
    • http://hunicorn.hu/userfiles/file/13879628714.pdfIn PDF document text
    • http://theexplorerthai.com/userfiles/files/74674540769.pdfIn PDF document text
    • http://intertermo.nl/userfiles/file/surovizomoxe.pdfIn PDF document text
    • http://donghotam.com/luutru/files/pelawaw.pdfIn PDF document text
    • https://fiberglasssupplydepot.com/userfiles/files/belowugop.pdfIn PDF document text
    • https://hn-as.dk/sites/default/files/userfiles/file/nesowaborez.pdfIn PDF document text
    • http://skupka23.ru/upload/m/zofomep.pdfIn PDF document text
    • http://mega-treid.com/userfiles/files/wexemabev.pdfIn PDF document text
    • http://www.heksan.com.pl/file/76739626931.pdfIn PDF document text
    • https://zippy-inc.com/app/webroot/userfiles/files/61073084109.pdfIn PDF document text
    • https://www.newhorizonscrisiscenter.org/ckfinder/userfiles/files/lomodefevasura.pdfIn PDF document text
    • http://kisito.com/userfiles/file/difilowad.pdfIn PDF document text
    • https://cambodiadriverservice.com/userfiles/file/banasegipiz.pdfIn PDF document text
    • http://xn--aknmedical-yub.com/uploads/file/14749640903.pdfIn PDF document text
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/1613ac27c42fa1---4380858588.pdfIn PDF document text
    • http://sbstroy53.ru/img/files/37229866069.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_off0000ada9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xADA9 14572 bytes
SHA-256: 7430318ec788d9ae5df584ea0be1811f024dd4a205c0ecdb658cb6240cbfa4d4
font_01_sfnt_off0000d25b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD25B 10748 bytes
SHA-256: 36e50ebd0cc2488cd864d6d418408c87da38ff91520be4f8a2cdcbb7adfa7b52
font_02_sfnt_off0000ead0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAD0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1