Malicious PDF — malware analysis report

Static analysis result for SHA-256 976f121c61e6d49b…

MALICIOUS

PDF

83.9 KB Created: 2021-09-18 09:20:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 8848df9d5c2898647a444469a57ced0f SHA-1: 7cb45fa05795f9b77ebc7dbafe56b1898a10848f SHA-256: 976f121c61e6d49bb495f73f098c6d85c76e2f12217672adc96f48a5ae958999
156 Risk Score

Malware Insights

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

The file was detected as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Static analysis revealed it functions as a link farm, containing numerous URLs pointing to compromised websites and potentially malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting and link farms, suggesting an attempt to manipulate search engine results or distribute malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161456eb204606---67628268380.pdf In PDF document text
    • https://www.isnb.co.uk/wp-content/plugins/super-forms/uploads/php/files/81d287d2aaf03b60dd6b3298b2df7532/15890635355.pdfIn PDF document text
    • http://umrllc.com/userfiles/files/lijuvedifewifi.pdfIn PDF document text
    • http://abwclayton.com/uploads/files/soruzasawokuxujowisifisu.pdfIn PDF document text
    • https://sunsoftinfoway.net/ckfinder/userfiles/files/zojuzubizokitobewudefivab.pdfIn PDF document text
    • http://jinwoosmc.com/userfiles/file/menexowudolule.pdfIn PDF document text
    • http://nessie-vinylcare.com/file/fiwejimeboxavabasujerar.pdfIn PDF document text
    • http://aodaiminhhanh.com/app/webroot/uploads/files/98335661848.pdfIn PDF document text
    • http://knshzj.com/CKEdit/upload/files/85733743632.pdfIn PDF document text
    • https://bushregenerators.net/userfiles/files/41858091660.pdfIn PDF document text
    • http://cozycornerexpress.com/uploads/files/77979005418.pdfIn PDF document text
    • https://kingbakerypans.com/userfiles/file/51386560715.pdfIn PDF document text
    • http://designklasse.de/ckfinder/userfiles/files/43912928919.pdfIn PDF document text
    • http://neodentpetrosino.it/userfiles/files/5324633696.pdfIn PDF document text
    • http://www.egavilanes.com/ckfinder/userfiles/files/penelu.pdfIn PDF document text
    • https://juvelyrikoscentras.lt/Files/file/pelafepibidaxikop.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/87ca479a6d42321f18efdd0220101beb/99370162313.pdfIn PDF document text
    • https://posh.hr/files/51988060926.pdfIn PDF document text
    • https://iveducentar.com/uploads/assets/file/fenepinuxupozunirifunesi.pdfIn PDF document text
    • https://loppisidjupdalen.se/images/uploaded/file/64534657123.pdfIn PDF document text
    • http://all-premium.com/user_file/files/lokilesupugezenenebugem.pdfIn PDF document text
    • https://sipare.com.ar/wp-content/plugins/super-forms/uploads/php/files/9btug80ufocqpjav1ascrd5m53/77785892797.pdfIn PDF document text
    • http://sharon-barron.com/userfiles/files/sowazegamofajewodanum.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=gangstar+new+orleans+openworld+hackPDF 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_off0000dd8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD8E 10920 bytes
SHA-256: 5524490746e17c78d04141bda5cfca3c73851ef8508e49fb15d28a9e0f8fbe82
font_01_sfnt_off0000f6b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6B8 19380 bytes
SHA-256: 2107504f3a0003490ba56b7385f1d87911ff80a10458b72165e86ad97e5f3fda
font_02_sfnt_off000129db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129DB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1