Malicious PDF — malware analysis report

Static analysis result for SHA-256 19c35bfdd541cfde…

MALICIOUS

PDF

87.1 KB Created: 2021-08-13 06:42:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 456bee5325c890c03c445e0be39baefd SHA-1: 95675e91d8286aa317ce2bb074dad7f7cb4f519f SHA-256: 19c35bfdd541cfde2a428d7fa478fcf32d77832c14f8dcb835bd567fa5946aac
156 Risk Score

Malware Insights

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

The sample is identified as malicious by ML classifiers and ClamAV, indicating it is a phishing or trojan PDF. It functions as a link farm, with numerous URLs pointing to compromised WordPress sites and other disposable hosting, likely to lure users into downloading further malicious content or phishing for credentials. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a tactic to improve search engine ranking for malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/2d56aa37731c50978f7d83b40b0d421e/pizunitemalezaza.pdf In PDF document text
    • https://sharidendesignasphalt.com/wp-content/plugins/super-forms/uploads/php/files/efab357dc02facd5b66194f8d96d3a17/24758826433.pdfIn PDF document text
    • http://pdww.ru/ckfinder/userfiles/files/wogagikumupabasosuxuw.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/2fd166e54d3e02fc50b7f9aa9e5692f8/mumubavamixapug.pdfIn PDF document text
    • http://kulturazebrak.cz/userfiles/ditidipomijiwima.pdfIn PDF document text
    • http://www.jucadent.es/ckfinder/userfiles/files/27502725952.pdfIn PDF document text
    • http://myexamadvisor.com/fck_uploads/files/33121132715.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160f7ecadb208c---munujab.pdfIn PDF document text
    • http://wenxuezj.com/images/File/busomogitetutuvixatig.pdfIn PDF document text
    • https://villatoscana-pi.it/userfiles/file/79830858200.pdfIn PDF document text
    • https://sbufficio.it/file/18944981987.pdfIn PDF document text
    • http://www.blackhillsdancecentre.com/wp-content/plugins/formcraft/file-upload/server/content/files/160884657d05d7---vufopixifodokuxejawaz.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160792524cd0e2---dotizemadarukerivekonome.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ce22f872eaf---33508551722.pdfIn PDF document text
    • https://guapa2.com/admin/fck/file/fomekerigomitetezejavu.pdfIn PDF document text
    • https://bibliotheque-des-arts.ch/ckfinder/userfiles/files/60968973751.pdfIn PDF document text
    • http://gabortech.com/admin/file/zebezopiravofosagubewus.pdfIn PDF document text
    • https://alphaveneers.co.uk/wp-content/plugins/super-forms/uploads/php/files/13f99a95331d7129335797e970d35c89/mobevimamonibojezus.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/7ebiv6e2n6c144k7n02eg8vhq7/fexevatobedukos.pdfIn PDF document text
    • https://ht-cooling-j3t.com/contents//files/lusiduxefobuvipimejimat.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=fundamentals+of+management+decenzo+agarwal+bhattacharya+robbins+pdf+downloadPDF 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_off0000e9d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9D8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000101ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101EA 17964 bytes
SHA-256: 7d7c3c126bd16ee88b0d39175d42999f2f8be28d64f1ccd66bbe8ef6a568410b
font_02_sfnt_off0001310e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1310E 11544 bytes
SHA-256: 6fe8729583199e884099d24e6c47bd5871b8a2059bad48404663dad5caa67d6c