Malicious PDF — malware analysis report

Static analysis result for SHA-256 7b11b0e6f5256b85…

MALICIOUS

PDF

89.8 KB Created: 2021-09-09 10:03:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: d56e3f78d713475365cccb305c7b9314 SHA-1: 51052689c4f5650b61cb704cb1a5d35170bb620a SHA-256: 7b11b0e6f5256b85bc74cdf9bc8bced8d46f3ef6f470d24f766892cdeab86545
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, with several heuristics indicating it functions as a link farm hosted on compromised or disposable domains. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO abuse. While no scripts were extracted, the structure and URL distribution point towards a malicious document designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

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 http://nensi.si/upload/file/gagolowu.pdf In PDF document text
    • https://partnermind.cz/images/files/veborivonakusavagi.pdfIn PDF document text
    • http://www.trimbleexpress.sk/wp-content/plugins/formcraft/file-upload/server/content/files/1613694f36f279---farepufegoj.pdfIn PDF document text
    • https://bunexim.dascalita.ro/app/webroot/files/userfiles/files/73023866132.pdfIn PDF document text
    • https://www.emcp-pmce.ca/_includes/ckfinder/userfiles/files/zudebikitavozolonukusix.pdfIn PDF document text
    • http://daiichilogistics.com/uploads/news_file/kufaxiguda.pdfIn PDF document text
    • http://nedvizhimost-v-sharm-el-sheikhe.ru/uploads/files/40853487824.pdfIn PDF document text
    • https://acconpriti.com/ckfinder/userfiles/files/79335897496.pdfIn PDF document text
    • https://novitas.ro/files/75219383521.pdfIn PDF document text
    • http://yachtales.net/admin/userfiles/files/luforoget.pdfIn PDF document text
    • http://gidaero.com/upload/fckeditor/file/bubilutetuxajekusewesaz.pdfIn PDF document text
    • http://rasciindia.com/firetech/ckupload/files/77292756329.pdfIn PDF document text
    • http://ntvietnga.com/upload/files/58958284224.pdfIn PDF document text
    • https://fallahi-sch.com/userfiles/file/lavorovizololuditadesol.pdfIn PDF document text
    • http://universalthailand.com/images/uploads/ckfinder/files/44010928001.pdfIn PDF document text
    • https://hoangphatdanang.com/uploads/image/files/62249839243.pdfIn PDF document text
    • http://weighlessthisyear.com/ckfinder/userfiles/files/24577344280.pdfIn PDF document text
    • http://saxonrt.hu/img/userfiles/files/78804379363.pdfIn PDF document text
    • http://energo-winstal.pl/userfiles/file/xogigogotuluxuditeg.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/rk1n0da2nmn6rq5q79lar6ej24/tupekeduxumivo.pdfIn PDF document text
    • https://pinkrali.com/calisma2/files/uploads/98961566789.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612ee56b9c4fd---dukisejojopefo.pdfIn PDF document text
    • https://doan295doson.vn/namthuan/images/news/files/wimufugapewinotetaz.pdfIn PDF document text
    • http://jiangsutravel.kr/userfiles/files/20210902_162423.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=horror+story+mode+gamesPDF 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_off0000fa99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA99 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000112ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112AB 18320 bytes
SHA-256: f1de4d73a4cd3c09037e2b6288cbcd35edbe73826463e62e51865aee955a7ff4
font_02_sfnt_off00014274.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14274 10452 bytes
SHA-256: f074df784660aeab29fb88c2bb50be8be31aaaf464218e0b7eedb1b3cd33490c