Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8bf1a18b8e28fb0…

MALICIOUS

PDF

80.4 KB Created: 2021-09-06 22:41:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 6217e3f78590ed3f80cffa2cc6bfc694 SHA-1: 5d188468df2ac6079171899d2deb285a2b34b0cd SHA-256: a8bf1a18b8e28fb039b74c7d8d742e9ece3dfb1ab95b2362e1df1dbe3feecf41
156 Risk Score

Malware Insights

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

This PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It functions as a link farm, containing numerous URLs that point to various websites. Some of these URLs are hosted on compromised WordPress upload directories or on domains identified as disposable, suggesting an attempt to lure users to malicious or deceptive content. The document body itself is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but containing embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://zhodnoceni-penez.cz/is/images/FCKeditor/File/bidazefelagutofipavej.pdf In PDF document text
    • https://learnrkb.jugalbandiresearch.com/ckfinder/userfiles/files/wovukulaputuraxepadolet.pdfIn PDF document text
    • http://phongkhamthienhoa.org/images/files/1418317218.pdfIn PDF document text
    • https://realestateconnect.biz/wp-content/plugins/super-forms/uploads/php/files/q0vvlhtt0nks23tv3mdp0jq1q3/vugasexaligoreniwebexasoz.pdfIn PDF document text
    • http://tcgardening.com/userfiles/file/2021080701103173499.pdfIn PDF document text
    • https://samsungklimalar.com/upload/ckfinder/files/34036595493.pdfIn PDF document text
    • http://saovietgroup.com/upload/FCK/file/senubigotapuxononalarador.pdfIn PDF document text
    • https://mcq-exambd.com/app/webroot/ckfinder/userfiles/files/dojimaf.pdfIn PDF document text
    • http://projectbudapest.hu/wp-content/plugins/formcraft/file-upload/server/content/files/16076248e889ca---26265986395.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1608227168eb30---funawijaxevutowigitimuji.pdfIn PDF document text
    • https://directorvincentchow.com/fck_filemanager_upload/file/rezakapitogubekofopukex.pdfIn PDF document text
    • https://theatresaucinema.fr/uploads/file/kerojagubuxoxapomibi.pdfIn PDF document text
    • https://actioncoach.com.my/wp-content/plugins/formcraft/file-upload/server/content/files/1606f3a769283c---repimodakuforujaxigi.pdfIn PDF document text
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/16094a518d4820---zadorejis.pdfIn PDF document text
    • https://kclandscapes.com/ckfinder/triplebuserfiles/file/kikexijeriwenunu.pdfIn PDF document text
    • http://dbcasagayathottam.org/assets/uploads/cms_images/files/61246588989.pdfIn PDF document text
    • https://restaurant-kamkok.fr/img/Data/file/79308880438.pdfIn PDF document text
    • http://osc-pribor.ru/products_pictures/file/16219920226.pdfIn PDF document text
    • https://apotekatia.ba/fajlovi/75484143114.pdfIn PDF document text
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7d283acc5---zexukusigefawusiwo.pdfIn PDF document text
    • http://www.amedna.com/userfiles/files/dujejodovazotusafoxolorev.pdfIn PDF document text
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/c56b2d9b9df4d9e0ded2a3f96b7dd211/vutolusema.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=exposure+response+prevention+techniques+pdfPDF 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_off0000d484.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD484 10904 bytes
SHA-256: ea72efc91a51bf337a6ce3f4e96cee2c51212f7efbcfbb513f662538e1bbce1b
font_01_sfnt_off0000ed86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED86 18060 bytes
SHA-256: 58b800a3d91c74b58dbdec9f41986cacc367adda2d286f5b69499333c183aa8d
font_02_sfnt_off00011b95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B95 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

Open this report in the interactive analyzer, or submit your own file for analysis.