Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8286ceda709fbb1…

MALICIOUS

PDF

67.9 KB Created: 2021-09-27 21:58:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: c3330953d0920f17fbcec757ec83000d SHA-1: 7e9d50db26b3ac0e6cf84eac85c0fc9e06ac8d06 SHA-256: f8286ceda709fbb1051d8a3d2f34a6d0f703d4ac9441fb35f6f56c109889dae0
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics strongly suggest this malicious intent. The ML classifier and ClamAV detection further confirm the malicious nature of the file, likely used for phishing or distributing further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://medvor.ru/uplcv?utm_term=free+spy+software+for+android+phone PDF link annotation
    • http://worldsocialistpartyindia.org/ckfinder/userfiles/files/27469491858.pdfIn PDF document text
    • http://studiocinti.eu/userfiles/files/gelidukisisopor.pdfIn PDF document text
    • https://mariellatriolo.it/public/file/10633310911.pdfIn PDF document text
    • https://akamercedes.com/images/uploads/files/11009650288.pdfIn PDF document text
    • http://www.enredmail.com/templates/files/idCliente_/file/tokugemazabubatikinima.pdfIn PDF document text
    • http://ediliziaunoaventi.com/userfiles/files/71251507021.pdfIn PDF document text
    • http://knx-shop.ru/admin/ckfinder/userfiles/files/73858646167.pdfIn PDF document text
    • http://gsnursing.in/ckeditor/ckfinder/userfiles/files/87579588288.pdfIn PDF document text
    • http://regmac.net/userfiles/files/43843287326.pdfIn PDF document text
    • http://zhongjiukeji.com/upload_fck/file/2021-9-21/20210921141958391720.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/1614261521b633---44037569315.pdfIn PDF document text
    • http://schturman.ru/files/files/geniloxutav.pdfIn PDF document text
    • http://cesishotel.com/res/wysiwyg/file/lebivesokasapowolezila.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140aebe387af---leruje.pdfIn PDF document text
    • https://chanty.dacola.com/upload/files/dokorazazelo.pdfIn PDF document text
    • http://xn--90aatbabxd8ae1kf.xn--p1ai/files/59293787292.pdfIn PDF document text
    • https://manorhair.com/uploads/files/202109211606092565.pdfIn PDF document text
    • http://qdxqw.com/uploadfile/file/85380355789.pdfIn PDF document text
    • http://skyrybupaslaugos.lt/uploads/files/4338343678.pdfIn PDF document text
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/16143a5cf604f5---ledifiboz.pdfIn PDF document text
    • http://arunimaflavours.com/userfiles/file/vuzepopudes.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_off0000ac83.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAC83 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c49a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC49A 10724 bytes
SHA-256: 786bfe66f23d76d6e9c7e5c8de24f48bc5f1459a05413bbe8e7138ce1fa947e3
font_02_sfnt_off0000dd40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD40 14628 bytes
SHA-256: e1d257fd37c4b0fedcd01d66a94989ab8abad41fb3a19f8d25cfe1bb0b9ed147