Malicious PDF — malware analysis report

Static analysis result for SHA-256 5f35dd222e36e1a7…

MALICIOUS

PDF

97.2 KB Created: 2021-09-16 14:12:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 19236373cc54c9743379b8fdb30481d0 SHA-1: f1c2be5e275c3cacbc09ab09529467ff35a8d4e9 SHA-256: 5f35dd222e36e1a7e298b6623c696c402b278601e12826d499b746808c4b7d52
204 Risk Score

Malware Insights

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

The sample is a malicious PDF containing embedded JavaScript, which is likely used to download and execute a second-stage payload. Several heuristics indicate the PDF contains links to compromised CMS upload storage and disposable hosting, suggesting a phishing or malware distribution attempt. The ClamAV detection and ML classifier further confirm its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 8

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138e9c590d1d---72035523992.pdf In PDF document text
    • https://dcoderesearch.com/uploads/4978494293.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/7foq0nd6lcc9gvnbaicb4ivsjk/jebituduwa.pdfIn PDF document text
    • http://greenvisioninternational.gm/userfiles/file/zizosevejavuxun.pdfIn PDF document text
    • http://modelseafarm.com/kweb/ckfinder/userfiles/files/66304866986.pdfIn PDF document text
    • http://coiffurenais.com/userfiles/file/47981768457.pdfIn PDF document text
    • http://topnotchimports.com/ckfinder/userfiles/files/90597178935.pdfIn PDF document text
    • http://ezclasssites.com/var/wwww/dev-ezclasssites-com/data/files/zijuguvo.pdfIn PDF document text
    • http://sunrui-ti.com/d/files/romozuf.pdfIn PDF document text
    • http://opuspointpartner.com/ckfinder/userfiles/files/gaxubax.pdfIn PDF document text
    • http://podlahypilat.cz/admin/file/66434727713.pdfIn PDF document text
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/78f0mc5as4055iub8ch44eut04/41590829017.pdfIn PDF document text
    • https://gesema.com/UserFiles/file/detujezividojegaxidajoro.pdfIn PDF document text
    • http://atreve.eu/ubezpiecz/obrazy/file/3710920174.pdfIn PDF document text
    • http://snap-drone.com/userfiles/file/xizodonomafonaleju.pdfIn PDF document text
    • https://chatsystem.site/js/ckfinder/userfiles/files/78402914280.pdfIn PDF document text
    • http://bbdecontra.com/userfiles/files/52722756298.pdfIn PDF document text
    • http://parfumland.sk/upl/jenuxodezenofonuvi.pdfIn PDF document text
    • http://panda-es.tokyo/yamituki-n/uploads/files/19848199685.pdfIn PDF document text
    • https://www.chablis-gautherin.com/ckfinder/userfiles/files/punasixivipaso.pdfIn PDF document text
    • https://huaku3c.tw/uploads/files/202109011648433390.pdfIn PDF document text
    • http://koreaseals.com/ckfinder/userfiles/files/mugewugepujixekuvoto.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=noam+chomsky+understanding+power+pdfPDF 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_off0001131d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1131D 11392 bytes
SHA-256: 9a605a6ea79ba3d08f691f11cc84ae438f8961aba37c017c1d4418d855e114b3
font_01_sfnt_off00012db3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12DB3 19168 bytes
SHA-256: a35c71ebb0017ccd782339442a0752a1526b59078e5ab66e49e2a9f57bf67455
font_02_sfnt_off00015eed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15EED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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