Malicious PDF — malware analysis report

Static analysis result for SHA-256 207da082e21990e6…

MALICIOUS

PDF

79.0 KB Created: 2021-10-09 17:06:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 4f997521ba49cedc6eee2c4b55e401b5 SHA-1: 5bb72b4a3a0df5c93e9c3193b9af65767a7445dc SHA-256: 207da082e21990e6422f8912a09c04208e17e23279199a0a4ad35f805abdb2be
156 Risk Score

Malware Insights

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

The PDF document contains a large number of embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content but serving as a container for the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://marlschuz.com/userfiles/files/53238973132.pdf In PDF document text
    • http://midoriku.zaitakunet.jp/app/webroot/upload_images/files/15935151051.pdfIn PDF document text
    • https://maintogelonline.bet/contents/files/xowipowomali.pdfIn PDF document text
    • https://aquariumfargo.com/wp-content/plugins/super-forms/uploads/php/files/62a73a304af76b6ae242a53377b50863/54301249586.pdfIn PDF document text
    • https://fajndoktor.cz/images/file/files/89689207867.pdfIn PDF document text
    • http://geyuping.com/geyuping/uploadfile/file/2021091321491773499.pdfIn PDF document text
    • http://budka39.ru/files/rugozevasenezokelunesa.pdfIn PDF document text
    • https://livnica-metalurg.com/images/pages/file/terunudo.pdfIn PDF document text
    • http://komodovo.ru/upload_picture/puzovifudonomi.pdfIn PDF document text
    • http://katachizu.com/img/news/files/62571398338.pdfIn PDF document text
    • http://thrifty-uy.com/files/others/80286862369.pdfIn PDF document text
    • https://olivierdaulte.com/ckfinder/userfiles/files/68970490381.pdfIn PDF document text
    • https://colegiumaniucarei.ro/ckfinder/userfiles/files/varuzuxujo.pdfIn PDF document text
    • http://adamlegal.com/userfiles/file/zorivaxizimod.pdfIn PDF document text
    • https://www.nitm.ac.in/nitmeghalaya/ckfinder/userfiles/files/43626497470.pdfIn PDF document text
    • http://lungshingcentre.com/userfiles/kanuwutijorakezamuvotamev.pdfIn PDF document text
    • http://businessnavigator.in/ckeditor/uploads/files/juribo.pdfIn PDF document text
    • http://execdentalclinic.com/uploads/ckfinder/userfiles/files/ladenomotofepod.pdfIn PDF document text
    • https://palezieux.com/ckfinder/userfiles/files/36987725599.pdfIn PDF document text
    • https://theemperorsoldclothes.co.uk/wp-content/plugins/super-forms/uploads/php/files/d55k866v7ummqteam2k523oofc/rerenelexa.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1614a13c6bf3e7---furik.pdfIn PDF document text
    • https://kingbakerypans.com/userfiles/file/55055222555.pdfIn PDF document text
    • https://www.idromeccanicasrl.com/idromeccanicasrl.com/wp-content/plugins/super-forms/uploads/php/files/acd815ac4da39eb464f0f48690596fb5/72914295181.pdfIn PDF document text
    • https://ventadeterrenosagricolas.com/userfiles/file/fukezafuzujituvapu.pdfIn PDF document text
    • https://www.sudoku-cool.com/ckfinder/userfiles/files/foxemewazevitekibawedom.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=factorization+problems+with+solutionsPDF 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_off0000c8f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8F6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e10d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE10D 11004 bytes
SHA-256: 4655133876c3c628ca38c856bdb6703a26ab95ddd5768c02e8fdb5286bd658d8
font_02_sfnt_off0000fa45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA45 19552 bytes
SHA-256: 5f3d1c6bb7cd73a0fa0d758139eb8e6e631fc9c0fa0770c14d8b4aa5b22ccc00