Malicious PDF — malware analysis report

Static analysis result for SHA-256 c211c438cc3ab947…

MALICIOUS

PDF

101.9 KB Created: 2021-07-19 07:41:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 51e352c0158b23d7e3a5e21c44f43a4c SHA-1: ef25c013772063751199e78138b8a778ce3c16a0 SHA-256: c211c438cc3ab94757617bbae6bc9ba0ed0979061e9f109ffd347e01919cf179
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous links pointing to compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. The presence of these links and the nature of the heuristic firings strongly suggest a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9803

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://claphamjunction.com.au/wp-content/plugins/super-forms/uploads/php/files/73872ce0a45df466746aa7f11023a6ae/63459537800.pdf In PDF document text
    • http://dighakanchaninternational.com/FCKeditor/file/37411353860.pdfIn PDF document text
    • http://recruiters-zone.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a96325a3b46---94780807740.pdfIn PDF document text
    • https://www.brightfieldbusinesshub.co.uk/wp-content/plugins/super-forms/uploads/php/files/na3gavteti1n7efbfn93peck35/16027115128.pdfIn PDF document text
    • http://www.ausafrica.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607cf867397aa---vagurebonifupevozex.pdfIn PDF document text
    • https://skinrepublic.vn/webroot/img/files/fipatesugitaguk.pdfIn PDF document text
    • https://vishalahospitality.com/ckfinder/userfiles/files/wopaju.pdfIn PDF document text
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609b7d343a805---rumapezepolebo.pdfIn PDF document text
    • http://w-f-l.de/user_img/file/tosiwukiripira.pdfIn PDF document text
    • https://saunadlaciebie.pl/userfiles/file/jukoguxoniwotu.pdfIn PDF document text
    • http://go-trec.com/wp-content/plugins/super-forms/uploads/php/files/qo8325uhu7qoqk74o0kup7vf3r/8129750651.pdfIn PDF document text
    • http://bafiti.com/sklep/userfiles/file/96365995571.pdfIn PDF document text
    • http://cnc-soustruzeni.cz/files/file/zoradakakalosimaj.pdfIn PDF document text
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/91c3fb4b93b1f82081272a07129eaa36/newejatekifukifopaj.pdfIn PDF document text
    • https://pankalconstructora.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d24cf278df5---22778432176.pdfIn PDF document text
    • https://www.aceitedeoliva.com/wp-content/plugins/super-forms/uploads/php/files/3cc16bd22eed5e5e7518ac34ca645b8b/madavolerodenabametipugu.pdfIn PDF document text
    • http://kapli74.ru/upload_picture/tuvegizoforeb.pdfIn PDF document text
    • http://dent-pro.cz/pic/file/vikefumepigelalepijiwukoz.pdfIn PDF document text
    • http://clear-es.net/yamituki-n/uploads/files/45444387331.pdfIn PDF document text
    • https://guijek.com/userfiles/file/1845998690.pdfIn PDF document text
    • http://php-lounge.de/userfiles/file/kokixokupodeta.pdfIn PDF document text
    • http://frangarcia.eu/upload/file/nivuwusarasuzijodo.pdfIn PDF document text
    • http://iccj.jp/images/uploads/fckeditor/file/83783661097.pdfIn PDF document text
    • https://cosplay-expo.it/ckfinder/userfiles/files/3491769002.pdfIn PDF document text
    • http://fqcycpa.com/jingkelun/userfiles/files/20210609112710.pdfIn PDF document text
    • http://mywymc.com/userfiles/file/9597001472.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=pickens+county+sc+tax+assessorPDF 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_off0001267f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1267F 18608 bytes
SHA-256: f82bb86f5fd32bbbc6e2430cf1c120f1ad09eb6872084e3e585debde4f8a9d69
font_01_sfnt_off000157e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x157E1 10588 bytes
SHA-256: 631e146e92988d89bfc512742c0e1f528e917c6bf6037a86fedf9aa5ccf094e5
font_02_sfnt_off0001704a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1704A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1