Malicious PDF — malware analysis report

Static analysis result for SHA-256 02a8cc72f944a714…

MALICIOUS

PDF

82.6 KB Created: 2021-09-10 18:08:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: dd9d7924b713fc911b3b0e2d9521549b SHA-1: 8bcc464e7401a1f367d49173b827ebf2931973cd SHA-256: 02a8cc72f944a714add357772bf9b829aae5411d6e68e7fdf57d94efb2bf549c
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to compromised WordPress sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to phish users or redirect them to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a vehicle for the embedded links.

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 http://pavcargo.ru/wp-content/plugins/super-forms/uploads/php/files/494e04c78af218d2e6f875cee0f97445/69121563840.pdf In PDF document text
    • http://retco.ge/ckfinder/userfiles/files/10519423533.pdfIn PDF document text
    • https://assignmentmart.com/ckfinder/userfiles/files/fesavebofaxulojorolitu.pdfIn PDF document text
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/16136955a71a04---32721037652.pdfIn PDF document text
    • http://www.santabriganti.org/admin/ckfinder/userfiles/files/74443536671.pdfIn PDF document text
    • http://officegate.biz/admin/fck_upload/file/61895132207.pdfIn PDF document text
    • https://calmoinc.com/upload/editor/file/dedolefunipigewumusi.pdfIn PDF document text
    • https://xn--fct5g39pjpo.tw/upload/leakstop/files/24537566485.pdfIn PDF document text
    • http://gleb777.com/fck_upload/file/67690941411.pdfIn PDF document text
    • http://jjw-led.com/userfiles/file/fudopujigetusinafado.pdfIn PDF document text
    • http://vektorma.ru/uploads/assets/file/16048789700.pdfIn PDF document text
    • http://china-spec.ru/userfiles/file/valegijiw.pdfIn PDF document text
    • https://aradmissions.com/ci/userfiles/files/78914406272.pdfIn PDF document text
    • https://minjar.mebel18.com/uploads/files/vagufiwozujefukivuji.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/2a0bfil73jk5q9fsss9ptde392/pejuviwatufosomi.pdfIn PDF document text
    • http://xn----8sbnbd9chja.xn--p1ai/userfiles/file/50302405226.pdfIn PDF document text
    • http://kimwendelldesign.com/ckfinder/userfiles/files/44477160000.pdfIn PDF document text
    • http://glassick.com/userfiles/file/76562990134.pdfIn PDF document text
    • http://btfa.tw/upload/files/88874537107.pdfIn PDF document text
    • https://uslugiinzynierskie.com/eurostyl/photos/file/69599829191.pdfIn PDF document text
    • http://morecoredesign.com/images/imageUps/files/26665048109.pdfIn PDF document text
    • http://fli.edu.mn/ckfinder/userfiles/files/mutogabagavewilulivivusis.pdfIn PDF document text
    • http://vindindex.nl/images/uploads/23539027807.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=words+to+describe+someone+that+start+with+bPDF 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_off0000dcfc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCFC 18100 bytes
SHA-256: b993f30bdce1cd2987df3e4cabef1644c7fc632ef01a1a098d27e81db43706a0
font_01_sfnt_off00010bb6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BB6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000123cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123CD 10808 bytes
SHA-256: 1cc91109513c19decf99351f35134e150f8284d63324f8db86128b5d33ece043