Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ee733885775ac97…

MALICIOUS

PDF

84.9 KB Created: 2021-08-31 15:19:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 5600f3ed03bfab6c12342ff594a51d65 SHA-1: 7f4f07d078beef5dc8a2ff831b6978cce6e7419d SHA-256: 4ee733885775ac978c51791c52a4cf59d14db19e6fd92e380374d1752c15a496
156 Risk Score

Malware Insights

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

The sample was identified as malicious by ML classifiers and ClamAV, flagging it as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS uploads. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9934

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://jgmurphy.com/wp-content/plugins/super-forms/uploads/php/files/0a14698781e86f41e2832ac8dc3abfcf/97973838209.pdf In PDF document text
    • http://www.veronicaneal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/16118ebd7e9a99---fudokujenatiruxaloso.pdfIn PDF document text
    • http://princeverma.in/uploads/files/rugudisetubi.pdfIn PDF document text
    • http://arredamentoambienti.it/img/file/fowagilikexakuwa.pdfIn PDF document text
    • http://autoscuolauniversale.it/userfiles/files/dipurezabureze.pdfIn PDF document text
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/1609119f918948---guvatarizoliwavawo.pdfIn PDF document text
    • https://fastcomputer.vn/wp-content/plugins/super-forms/uploads/php/files/47b9de17d0f2d4c79a0ae082ef99e895/roripe.pdfIn PDF document text
    • https://rabudiagnostic.com/userfiles/files/bofuwamabevuru.pdfIn PDF document text
    • http://china-zub.ru/userfiles/file/sixari.pdfIn PDF document text
    • https://hashtag.school/userfiles/file/fagaxefawajojif.pdfIn PDF document text
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/296f427219816ff1d3b4b595280b9537/zulesesakowovexij.pdfIn PDF document text
    • https://lokmangal.co.in/wp-content/plugins/super-forms/uploads/php/files/6ef6aaf87e0b2f20468cd65329a4ca0f/xozewiguki.pdfIn PDF document text
    • https://edarky.net/data/file/48398232217.pdfIn PDF document text
    • https://erdenetpost.mn/userfiles/files/gopulaxir.pdfIn PDF document text
    • https://choiceenergynetwork.com/wp-content/plugins/super-forms/uploads/php/files/2c8230c05006e3d12a50eb1587232bf1/sipapuzofidajivexog.pdfIn PDF document text
    • http://ideviceplus.be/app/webroot/files/userfiles/files/nomawunulugejivujoza.pdfIn PDF document text
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/6b2a95ad224b7edbe46f282357981bcb/lezavewogavige.pdfIn PDF document text
    • https://sketchup360.vn/wp-content/plugins/super-forms/uploads/php/files/nl0opu62hlu7peqs2s7hn9bb57/4266254487.pdfIn PDF document text
    • http://c2mag.com/wp-content/plugins/formcraft/file-upload/server/content/files/16079cf81638d3---garovesakafesufevu.pdfIn PDF document text
    • https://amursvoidom.ru/media/files/fenibofodexifaragevenejor.pdfIn PDF document text
    • https://cahayaapi1.com/contents//files/runudul.pdfIn PDF document text
    • https://searchkar.com/ci/userfiles/files/43035090063.pdfIn PDF document text
    • http://laptopplus.be/app/webroot/files/userfiles/files/rubegalesube.pdfIn PDF document text
    • https://www.bluegreenshouseboats.in/wp-content/plugins/formcraft/file-upload/server/content/files/160b671fbef99f---penupunuwebapinukotuloma.pdfIn PDF document text
    • https://sicurezzaips.it/uploads/file/19677195396.pdfIn PDF document text
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160d8d1152fcf4---keduzumamizifusit.pdfIn PDF document text
    • http://purepoem.com/resource/docContentImg/file/2021-08-07/eaa679981c79a5a00cf0a7a1d3b4fb97.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=myocardial+infarction+and+atherosclerosisPDF 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_off0000ea0d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA0D 10680 bytes
SHA-256: 98b1488b7aa8938c42e6b0f0133407246aeca91be1a0c0fa355508248c02b307
font_01_sfnt_off00010279.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10279 16524 bytes
SHA-256: f44efdd852ecd8fdd363112dc608eb44dfa5af3ee1491a5810b4d62801c8501b
font_02_sfnt_off00012d20.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D20 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1