Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c15f0017023c757…

MALICIOUS

PDF

67.5 KB Created: 2021-09-25 07:31:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 5f0b9ccf15b49ad425b42a1b2617894d SHA-1: b344f8d7fd0c255e57de8b187a6a6571adc3c20f SHA-256: 8c15f0017023c757659d8c8186c315d7d2aefdc25cd96d4bd5a1285a3864065c
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file contains embedded JavaScript and numerous external URIs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. The embedded JavaScript is likely responsible for executing the redirection or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9966

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://hengtaixin.com/HangShun/ckfinder/userfiles/files/79205305676.pdf In PDF document text
    • http://solarexperte.ch/fckeditor/editor/images/file/92028250707.pdfIn PDF document text
    • https://www.institutvzdelavani.cz/files/29774183491.pdfIn PDF document text
    • https://eduinfinite.com/wp-content/plugins/super-forms/uploads/php/files/c0719e2c587adf25548eba98adf9fc3e/kesivixidowutovum.pdfIn PDF document text
    • http://suachuamaydemtien.biz/userfiles/file/99721161528.pdfIn PDF document text
    • https://growmytruck.com/wp-content/plugins/super-forms/uploads/php/files/0eb0b00f21f527988272a9b332d236b1/nowetugagafolaxa.pdfIn PDF document text
    • https://piauiaqui.com/ckfinder/files/tetajejutuburofubokolakot.pdfIn PDF document text
    • https://olivierdaulte.com/ckfinder/userfiles/files/dofipuromebemujegimenoza.pdfIn PDF document text
    • http://vmkmsz.hu/userfiles/file/52382132024.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/16135f17c4bcd6---xanojamige.pdfIn PDF document text
    • https://nomaquito-travel.com/editor-images/50071651639.pdfIn PDF document text
    • http://dija.lv/public/userfiles/file/weveliwufulozoginogaku.pdfIn PDF document text
    • https://ln80.cn/filespath/files/20210914083104.pdfIn PDF document text
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16145c11e6d7df---69172323049.pdfIn PDF document text
    • http://epoch-making.jp/js/upload/files/vekure.pdfIn PDF document text
    • http://erodiertechnik-wenzel.de/userfiles/file/noweditup.pdfIn PDF document text
    • http://saharun.org/uploads/ckfinder/userfiles/files/70172613973.pdfIn PDF document text
    • http://veitali.com/upload/files/zizemovawawaxubufibolefe.pdfIn PDF document text
    • http://kbchina.de/upload/58358993622.pdfIn PDF document text
    • http://przychodnia-felinskiego.pl/uploads/editor/file/47927841259.pdfIn PDF document text
    • http://easyliveconstruction.com/ci/userfiles/files/guweduvositalen.pdfIn PDF document text
    • https://multimetrics.com/ckfinder/userfiles/files/4678650279.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=1234+go+moviesPDF 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_off0000acc3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xACC3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c4d5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC4D5 14424 bytes
SHA-256: 5f68505deb5f44ce13d682daf281745155f7ae806f873e5416c2d2123df80703
font_02_sfnt_off0000e941.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE941 10332 bytes
SHA-256: de1023b9b503c0f46df23cf923a5ba165a9c9b533d27c691ca0048aad7d03060