Malicious PDF — malware analysis report

Static analysis result for SHA-256 da11cd509aa743c9…

MALICIOUS

PDF

80.9 KB Created: 2021-09-24 05:56:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 0d4bff5734cfaeb85f6f00672a0b3b1a SHA-1: 938ea6bc247ab5c6a7195608f9f22acbb9ceff0e SHA-256: da11cd509aa743c9ae4124cc377c7297f555ed0f4ca6db7199b0d94076f8f423
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier 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 WordPress installations. The embedded URLs and the nature of the heuristics suggest the primary goal is to redirect users to malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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 https://laborke.ru/uplcv?utm_term=does+an+android+sim+card+work+in+an+iphone PDF link annotation
    • http://elistaprezentow.pl/userfiles/file/6405685170.pdfIn PDF document text
    • https://gilbertems.com/videos/file/37907540787.pdfIn PDF document text
    • http://indcms.testingmachines.com/images/file/rirerikinazolumowukuj.pdfIn PDF document text
    • http://esen-life.com/userfiles/file/86186320600.pdfIn PDF document text
    • http://jockmurray.com/wp-content/plugins/formcraft/file-upload/server/content/files/161413da7421c2---wufoxivorumokiwa.pdfIn PDF document text
    • http://heathrowairporttaxi.website/userfiles/file/dokesubad.pdfIn PDF document text
    • https://flcevent.fcu.edu.tw/plugin/ce1/ckfinder/userfiles/files/20210911022028.pdfIn PDF document text
    • http://aygroupmuh.com/image/files/wividexusajo.pdfIn PDF document text
    • https://vallejardin.com/wp-content/plugins/super-forms/uploads/php/files/2c1230569b8f59061b4c9ceab5332e0f/32164336627.pdfIn PDF document text
    • http://yule-sign.com/upload/editor/file/20210908232443.pdfIn PDF document text
    • http://www.schule.havonix.com/ckfinder/userfiles/files/97857473780.pdfIn PDF document text
    • http://homokkepek.hu/editor_up/kategev.pdfIn PDF document text
    • https://yasacompany.com/upload/files/10594625171.pdfIn PDF document text
    • https://diarch.in/WYSIWYGImage/file/morimurate.pdfIn PDF document text
    • https://www.bmo-agencement.fr/ckfinder/userfiles/files/padodevoko.pdfIn PDF document text
    • http://studiocinti.eu/userfiles/files/66336965890.pdfIn PDF document text
    • https://www.burit.net/wp-content/plugins/formcraft/file-upload/server/content/files/161335904c8ad7---54827935440.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_off0000d66d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD66D 18104 bytes
SHA-256: 3a24524817963ed169ddebb9a616c7270b896e58914762eb3eee819495c0a99b
font_01_sfnt_off00010590.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10590 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011da7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DA7 10812 bytes
SHA-256: e0bf1461aab2603855e25f5fa9a7a51a058020354d287105ec9803c98c68465b

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