Malicious PDF — malware analysis report

Static analysis result for SHA-256 b750f74ffe4b57dd…

MALICIOUS

PDF

73.4 KB Created: 2021-09-17 15:47:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 645a6212d1392697f0c08bf89e464d19 SHA-1: ee342c41a86a1b694172b625549d5d91e4defd87 SHA-256: b750f74ffe4b57dd388c4ac18af73bf193c6afe965cced73fe3421c896bfeaa6
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains an embedded JavaScript stream and numerous external URIs, many of which point to potentially compromised websites or disposable hosting, indicative of a link farm. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or SEO poisoning to redirect users to harmful content. The embedded JavaScript is likely used to facilitate the redirection or exploit vulnerabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 7

  • 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.
  • 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://gzhangqin.com/uploadfile/files/76203189300.pdf In PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/gghle3891pcb5is1iiqovmg722/kumona.pdfIn PDF document text
    • https://kabelkyaobuv.sk/editor_uploads/files/mexukafobixorenafolunegi.pdfIn PDF document text
    • http://inspiredindianfoundation.org/uploads/zifidaxomamoduj.pdfIn PDF document text
    • http://maychaybocaocap.com/app/webroot/uploads/files/zifogixunavu.pdfIn PDF document text
    • http://big-blue-bus.com/pics/fotos/1/file/52356965373.pdfIn PDF document text
    • http://suurelepa.ee/data/file/dipani.pdfIn PDF document text
    • https://megashina24.ru/files/files/dokozuzenup.pdfIn PDF document text
    • http://www.ishvani.com/www/js/ckfinder/userfiles/files/42988986269.pdfIn PDF document text
    • http://ailizia.com/userfiles/48804476003.pdfIn PDF document text
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/g74a5np964q3ba6vg8335rdk94/91668921526.pdfIn PDF document text
    • https://drlalashow.com/php/billboard/uploads/file/bugotosujafukiboseti.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/16133a8827b0ba---67002534596.pdfIn PDF document text
    • http://www.tenniscanberra.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161396c45178ee---zofeza.pdfIn PDF document text
    • http://alda.pl/ckfinder/userfiles/files/71924554586.pdfIn PDF document text
    • http://www.ppk-kp3k.kkp.go.id/ver2/extra/ckfinder/core/connector/php/media/ckfinder/files/wezaruloxutu.pdfIn PDF document text
    • https://playindiano1.in/ckfinder/userfiles/files/falekolusalaxufunutowunan.pdfIn PDF document text
    • http://busankid.com/webfiles/board/file///danoruvo.pdfIn PDF document text
    • http://brukikostka.pl/uploads/page/file/japezokulegenamuno.pdfIn PDF document text
    • http://www.first-classlogistics.com/image/upload/File/24177065665.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=how+to+add+apps+to+lock+screen+androidPDF 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_off0000bc21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC21 10676 bytes
SHA-256: 992fc3ae3b0863fb83c7361b87c13880c0feba0bf007da78a2d06732aa5a7357
font_01_sfnt_off0000d4bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4BF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ecd1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECD1 16824 bytes
SHA-256: 78b2fa0084a2fe2d383ad63dead7c1de14866e114bc2ee738c588ad5b8b05c3d