Malicious PDF — malware analysis report

Static analysis result for SHA-256 ab9ce92c0d381be9…

MALICIOUS

PDF

107.4 KB Created: 2021-09-24 11:18:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 430815b8bc171328f246073e6f05834f SHA-1: 7187b328fc93e10c8e4b3bf3bf96359caaae8226 SHA-256: ab9ce92c0d381be9e5f020644ef426fc12f4a5680a0324d8078ff45b78b9a04d
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly indicate malicious intent. The primary attack pattern involves directing users to external, potentially malicious, content via a link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9822

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://nguyenthelong.net/userfiles/files/11335601834.pdf In PDF document text
    • http://frutapacargentina.com/ckfinder/userfiles/files/70613399670.pdfIn PDF document text
    • https://kabelkyaobuv.sk/editor_uploads/files/waxeruwetitekififeramu.pdfIn PDF document text
    • https://betamachinery.sa/other_files/File/lunefepepokugom.pdfIn PDF document text
    • https://alistairmills.com/ckfinder/userfiles/files/91496660329.pdfIn PDF document text
    • http://www.mbk-montage.nl/ckfinder/userfiles/files/getinebonoj.pdfIn PDF document text
    • http://civicwomen.com/ckfiles/files/dixobuwotesexozereruxaf.pdfIn PDF document text
    • http://dga.gr/ILC/img/file/wobutigam.pdfIn PDF document text
    • https://rhuyscampingcar.fr/images/files/rupimasusirapeferi.pdfIn PDF document text
    • https://www.pension-chevaux-haras-gabereau.fr/ckfinder/userfiles/files/bugizuxenemamonofoxivujef.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/1613944bb4fa39---tibas.pdfIn PDF document text
    • http://tverzhilservis.ru/foktver.ru/ckfinder/userfiles/files/tinaridatura.pdfIn PDF document text
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/1613d98c51e2f1---tidigejoruselu.pdfIn PDF document text
    • http://dkkarsin.pl/img/upload/files/zurexevave.pdfIn PDF document text
    • http://ansing.nl/userfiles/file/buwukanak.pdfIn PDF document text
    • http://seednseed.com/admin/fckfiles/file/74831485338.pdfIn PDF document text
    • http://thelifelesson.net/home/tappingchanges/public_html/dowalumniusa/ckfinder/userfiles/files/67286648366.pdfIn PDF document text
    • http://nhakhoasaigonkimcuong.com/uploads/images/files/xupunovekukuviratawawifov.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c06935569a---15333710874.pdfIn PDF document text
    • http://notariocprietoa.com/notaria/documentos/files/lobevarunelufisewufiputo.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16147c05baf0af---81109009929.pdfIn PDF document text
    • http://kino-profi.com/wp-content/plugins/super-forms/uploads/php/files/31a6ab64584cf7c8e942b0ff876519de/xupapat.pdfIn PDF document text
    • http://yilip.net/userData/board/file/79535498336.pdfIn PDF document text
    • https://www.keystonecare.co.uk/wp-content/plugins/super-forms/uploads/php/files/223151edc68a8df1b72e677ed1f55057/tikugonajomidutex.pdfIn PDF document text
    • http://arcenevents.nl/site/upload/files/nofomuxefavujutiku.pdfIn PDF document text
    • https://cambodiadriverservice.com/userfiles/file/lubiguxoka.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=50+shades+of+gray+download+for+freePDF 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_off00013cd8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13CD8 19092 bytes
SHA-256: 2842653fca8e9f0c34487a0204630b9a603ed7e229475884bc8eef444f7a4b35
font_01_sfnt_off00016f24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16F24 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001873b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1873B 10800 bytes
SHA-256: 04b0fb033e810f11eb9dcf3b904128c511faf07bab4989455eed77002f1fd018