Malicious PDF — malware analysis report

Static analysis result for SHA-256 99f1d22018df17e9…

MALICIOUS

PDF

72.5 KB Created: 2021-09-18 12:19:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 950fc4a856f42b8d46be1bd729a6ed3b SHA-1: 40bbe7ef7f360f44c7d2ef74f1b37d05777db78e SHA-256: 99f1d22018df17e9ed0b38bab33d57548336e09bcf52091e1763f87c2b9f82fb
156 Risk Score

Malware Insights

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

The PDF file contains a link farm pointing to multiple disposable hosting sites, a common tactic for phishing and malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of numerous PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this, suggesting the document is designed to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://www.studioline.ie/ckfinder/userfiles/files/tetuvaxajosufedipibojabim.pdf In PDF document text
    • http://kocavietnam.com/upload/files/tekexavebun.pdfIn PDF document text
    • http://dentalweek.eu/userfiles/files/dujibe.pdfIn PDF document text
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16140ec19f3000---69267587903.pdfIn PDF document text
    • https://parisautotravel.com/wp-content/plugins/super-forms/uploads/php/files/8bbiip6ok9e4eb8l54suhurk71/23682694415.pdfIn PDF document text
    • https://lotteppta.net/beta/assets/file/5596984920.pdfIn PDF document text
    • http://eis-pieschel.de/UserFiles/File/mavavofedilowupulojokupi.pdfIn PDF document text
    • http://goldartline.ua/userfiles/file/59978513902.pdfIn PDF document text
    • https://puertoestereo.com/wp-content/plugins/super-forms/uploads/php/files/a8b8lhh8vhkvlst32n0gsireiu/genezuwejipoxikovumobetip.pdfIn PDF document text
    • http://kleinschaden-expert.com/userfiles/file/95611689160.pdfIn PDF document text
    • http://kuppersbusch.hu/userfiles/files/56161083470.pdfIn PDF document text
    • https://segurodegranizo.ar/noticias/fckeditor/file/renodibuwomunoson.pdfIn PDF document text
    • https://drakbera.com/ckeditor/ckfinder/userfiles/files/11961223447.pdfIn PDF document text
    • http://purepassion.pl/userfiles/file/64129486470.pdfIn PDF document text
    • http://auto-rad.pl/userfiles/file/saxabepivax.pdfIn PDF document text
    • http://aedjtjdshbf.pretty-match.com/upload/files/95799779857.pdfIn PDF document text
    • http://henghuitong.com/jingkelun/userfiles/files/20210907233127.pdfIn PDF document text
    • http://erex.hu/upload/file/89602415868.pdfIn PDF document text
    • http://alrabbanoilandgas.com/file/files/69562288908.pdfIn PDF document text
    • http://agppi99.pretty-match.com/upload/files/11877479128.pdfIn PDF document text
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a73a240d20---xipigunilijujalitivan.pdfIn PDF document text
    • https://podgoricki-klub.me/userfiles/file/minogirasiwuvuxavolev.pdfIn PDF document text
    • http://waterlootour.com/FileData/ckfinder/files/20210907_62126C86E779822B.pdfIn PDF document text
    • http://xn----9sbkvfu2aex3d.xn--p1ai/ckfinder/userfiles/files/sukumo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=xender+2021+apk+downloadPDF 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_off0000bad3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBAD3 16448 bytes
SHA-256: bdef8a44c0b407101f4ee82f7a2c5e710fc57fe8a50b4f08ec837016685f5077
font_01_sfnt_off0000e4a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4A3 10508 bytes
SHA-256: f1cf3b0bf9c4b4caef4c000f3266605626f01bda9ac951a1f980f948f1438a06
font_02_sfnt_off0000fcbc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCBC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1