Malicious PDF — malware analysis report

Static analysis result for SHA-256 ddf62b53a3c70855…

MALICIOUS

PDF

77.0 KB Created: 2021-09-16 20:45:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 9fd5c0a7bcc89d795e8c5c5a297ff2fb SHA-1: 6b9b38dcc392d97508177fbdaefde6367dbfb5a0 SHA-256: ddf62b53a3c7085536d45fcfa0eb301ba60906dc38f3837b8a2cda07ff05a560
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS uploads. The document body is heavily obfuscated and contains no readable content, suggesting its primary purpose is to host these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://weifong.tw/fckimages/file/fixirifadekemajabaredeje.pdf In PDF document text
    • https://karolinanowak.com/userfiles/file/vasixi.pdfIn PDF document text
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b2907d7fd7---japobusedapebipasagezonuv.pdfIn PDF document text
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161421d125ab7e---gopuxi.pdfIn PDF document text
    • http://www.oteliapelsin.ru/ckfinder/userfiles/files/44675602988.pdfIn PDF document text
    • http://studiodrago.eu/userfiles/files/66768546710.pdfIn PDF document text
    • https://hensuyenpqa.traigiongthuha.com/ckfinder/userfiles/files/29890880827.pdfIn PDF document text
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134f5d0d3709---wajozinenugadasaberukadod.pdfIn PDF document text
    • https://dobre-akce.cz/media/files/file/jatejufugojinesazesis.pdfIn PDF document text
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1612f7a4413649---miwaveba.pdfIn PDF document text
    • http://ajej.pretty-match.com/upload/files/bezetamuwi.pdfIn PDF document text
    • http://esistore.be/userfiles/file/72423820070.pdfIn PDF document text
    • http://ladispensadicampagna.it/uploads/assets/file/lojopifexitaw.pdfIn PDF document text
    • https://iphastkala.com/userfiles/file/69981660256.pdfIn PDF document text
    • http://blesk-stroy.ru/userfiles/files/kotefapekufata.pdfIn PDF document text
    • http://dishandspoonproductions.com/ckfinder/userfiles/files/31099426523.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614234b4c1651---texibopeselavix.pdfIn PDF document text
    • https://gs-hemeringen.de/ablage/userfiles/files/fadujewenunijelazi.pdfIn PDF document text
    • https://serviceelectric.ca/userfiles/file/26474692909.pdfIn PDF document text
    • https://scavilecis.it/userfiles/file/79208354274.pdfIn PDF document text
    • https://inprovitmexico.com/ckfinder/userfiles/files/62939722165.pdfIn PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/p8kd4mrsc3ngfqrfgk7dvam5rt/98503626293.pdfIn PDF document text
    • http://siripanyalamphun.com/user_img/files/wewomowovimuki.pdfIn PDF document text
    • http://twinmd.ru/userfiles/file/47243354905.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=swype+keyboard+iosPDF 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_off0000c9d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9D4 17108 bytes
SHA-256: 02ede074ebe5b59633ee6ef9178b2c05ac6591d90caa4b0dae1260a83676e81f
font_01_sfnt_off0000f60c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF60C 10644 bytes
SHA-256: e84c8e1889b5f74753959f6c1e817fbcc76c2d499ba6b983c7664438783f1adc
font_02_sfnt_off00010e60.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E60 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1