Malicious PDF — malware analysis report

Static analysis result for SHA-256 71cb2264dc970314…

MALICIOUS

PDF

68.5 KB Created: 2021-05-18 20:38:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-29
MD5: fc70f7a3d9bbbb9fb664a98259c21bf4 SHA-1: 3b86bceb84c16ffb037f2c6c776713de1e37bef7 SHA-256: 71cb2264dc970314fb3fe96ed87bab7e5ceae1f8a68666a5be73d462e92fabbb
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to compromised WordPress upload directories. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, and the URLs themselves are designed to lead users to potentially malicious content hosted on compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606edd3b076ae---75004538169.pdf In PDF document text
    • https://leo-translate.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/16092d98bd4119---51378619389.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/ladebawagafuzo.pdfIn PDF document text
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/1s4j2htidsmdab0cf5448b9eb4/vipazojem.pdfIn PDF document text
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160841c24dab30---10831938856.pdfIn PDF document text
    • https://mebelpozakazu.ru/wp-content/plugins/super-forms/uploads/php/files/68b2eacaebfc2a830af4d097c89e9b08/vedamido.pdfIn PDF document text
    • http://jevades.com/aircraft/fckimages/file/50155771126.pdfIn PDF document text
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/f2cd9482e353a86c2654ff0d8d253969/waduluwobexopudumoni.pdfIn PDF document text
    • http://vincityhomes.vn/wp-content/plugins/super-forms/uploads/php/files/jnnfju5sv2nr0ishta5ahhs5rs/85371823578.pdfIn PDF document text
    • https://lashmakerpro.it/wp-content/plugins/super-forms/uploads/php/files/2bus78r4ur0a4eoiuvblc3s7o2/wizuwewuxibonebasa.pdfIn PDF document text
    • https://rlvanstory.com/wp-content/plugins/super-forms/uploads/php/files/d112827cbccfc32f7268fd52ce302d7f/tisopenalowetodaxijaresi.pdfIn PDF document text
    • https://elicopter-de-inchiriat.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607816f0400e0---gegabababimu.pdfIn PDF document text
    • http://aksaaydinlatma.com/img/editor/image/file/32483622993.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=how+to+cook+fries+in+farberware+air+fryerPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d035.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD035 5200 bytes
SHA-256: 66f0f5599cc62fc65d4b150cfccb509b78887bbbd8612dc66865e55621e8b6e7
font_01_sfnt_off0000e214.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE214 10320 bytes
SHA-256: 1cf91e4a9982726857efb5670c3c2c50425ccc78f4f2f896669cb9ce7b36eefe