Malicious PDF — malware analysis report

Static analysis result for SHA-256 85e9b34f5bc11226…

MALICIOUS

PDF

81.6 KB Created: 2021-09-02 14:15:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 0cfca78e2674d2bf96a5833b9958638a SHA-1: 69d0da2b4bc3064a494d0d11d2d5519c285e79fc SHA-256: 85e9b34f5bc11226752fb24126921c4e8101f438c2f11ee05a620f9a6f251ebf
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file is identified as malicious by ML classifiers and ClamAV, with multiple heuristics indicating it functions as a link farm. The URLs point to a variety of domains, including compromised WordPress sites and disposable hosting, suggesting a phishing or malware distribution scheme. Although no scripts were explicitly extracted, the PDF structure and the nature of the URLs strongly suggest an attempt to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 https://crewmak.ru/uplcv?utm_term=online+editing+pdf+file+free PDF link annotation
    • http://numere-mopede.ro/mm/file/gagolevofiki.pdfIn PDF document text
    • https://x-leather.com/radsportfiles/file/favazalemikozesiz.pdfIn PDF document text
    • http://westfallassociates.com/documents/file/5851882960.pdfIn PDF document text
    • https://pnp-studio.com/fckeditorfiles/file/zitanuwowarividozuravezu.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607c97bc2f9a5---15160736821.pdfIn PDF document text
    • https://elitstroycraft.ru/source/file/detefazakikuse.pdfIn PDF document text
    • http://chongthamnguoc.vn/img/files/tapavukabogino.pdfIn PDF document text
    • http://vandientuchinhhang.com/upload/files/jowub.pdfIn PDF document text
    • https://klubkanine.com/home/klub/public_html/ckfinder/userfiles/files/jolivevobesudime.pdfIn PDF document text
    • http://mtcclassof81.com/clients/0/0a/0a45bd3013a8cc77df817aa526a911b1/File/6167760738.pdfIn PDF document text
    • http://meechoktoolmart.com/user_img/files/52514927125.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/c8dee6de897a624c453e2f5e4e6b6af0/66562933913.pdfIn PDF document text
    • http://juicewarenhuis.nl/app/webroot/files/userfiles/files/vivavasija.pdfIn PDF document text
    • http://eko-inwest.eu/upload/file/vuxowokinazotemuligo.pdfIn PDF document text
    • http://studiotipaldo.com/userfiles/files/74216089023.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094a1c80cebf---jiwej.pdfIn PDF document text
    • https://beaufortbond.com/wp-content/plugins/super-forms/uploads/php/files/634971a9cee47d6a60ceb7e7a56ddb0e/xekez.pdfIn PDF document text
    • https://mytekas.com/UserFiles/file/wefewedaxotaz.pdfIn PDF document text
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/2bfed69ef6ee4c3847a614746fb6daa1/saxalodelagerima.pdfIn PDF document text
    • https://doanhnghiepvietnam.org/img_duhoc/files/91097478696.pdfIn PDF document text
    • https://0a3exp.com/upfiles/editor/files/lubafexafepuvijuwimuba.pdfIn PDF document text
    • https://evboosters.com/wp-content/plugins/super-forms/uploads/php/files/f2cf3c990e6363ee2045f4463d12af1f/memaxeferelijelaza.pdfIn PDF document text
    • http://purpledoorchurch.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca08c0fd17---2747021310.pdfIn PDF document text
    • https://www.letspassdriving.co.uk/wp-content/plugins/super-forms/uploads/php/files/n99sk0s44ur3pgu40llcs8qefr/27260541079.pdfIn PDF document text
    • 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_off0000dcbb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCBB 17460 bytes
SHA-256: e9e11421ed3371209587b3e56d1d4ccf0a149fc28ea2df329b992a88b7c6de64
font_01_sfnt_off000109ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109BA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000121d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121D1 10248 bytes
SHA-256: f461e6fb4be5ca254a3a14e80871e9719adf5e063e2cb44aeb6713b785434849