Malicious PDF — malware analysis report

Static analysis result for SHA-256 3844b86f9229fa44…

MALICIOUS

PDF

71.3 KB Created: 2021-09-17 12:53:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: f22af594864d9036e37b6c938dbaeb6f SHA-1: 421710fad35579dbe2bcd4679b95f58990106681 SHA-256: 3844b86f9229fa4450da25160537e4f61c607eb073429baaa913bc96f0880327
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, and the document body was unreadable, but the heuristic firings and URL analysis are sufficient to assess the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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.entornopublicitario.com/wp-content/plugins/super-forms/uploads/php/files/f336948ec8b9379f7b8b9ff1c5145de8/wabidiriboresiparofu.pdf In PDF document text
    • http://terwaarde.be/ckfinder/userfiles/files/66485105510.pdfIn PDF document text
    • http://rideco.hu/upload/file/17895023435.pdfIn PDF document text
    • https://semot.com/Store/userfiles/file/49688782595.pdfIn PDF document text
    • http://www.gonouvellezelande.com/files/buleranunusikabarija.pdfIn PDF document text
    • http://burbank.kopanramen.com/uploads/files/78420386693.pdfIn PDF document text
    • http://thuexedanang247.com/uploads/image/files/jerulirapu.pdfIn PDF document text
    • https://tidurmalam2.com/contents/files/sujesavulusaxabenujuzot.pdfIn PDF document text
    • http://yh-nutri.com/filespath/files/20210903063211.pdfIn PDF document text
    • http://xsteelstock.com/d/files/61962659127.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bc5c406d22---42673150765.pdfIn PDF document text
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138fc6e01976---rikibugazinawikorisof.pdfIn PDF document text
    • https://zagi.hr/files/nizuxakidanazuzaxine.pdfIn PDF document text
    • http://hanasushimenifee.com/uploads/files/48104418050.pdfIn PDF document text
    • https://gretajensen.com/ckfinder/userfiles/files/bisozebedokufosinipo.pdfIn PDF document text
    • http://www.yankey.com.tw/demo/public/editor/ckfinder/upload/user_upload/files/89889218340.pdfIn PDF document text
    • https://www.sophrologue-nimes.fr/upload/news/files/nulib.pdfIn PDF document text
    • http://rsport.eu/yonexshop/static/file/69791645818.pdfIn PDF document text
    • http://ecoevopublisher.com/files/upfiles/file/denojajes.pdfIn PDF document text
    • http://ctkupavna.ru/upload/file/lodajapanugesigexake.pdfIn PDF document text
    • http://cheniou.handysociality.com/upload/files/5300870944.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=the+fighterman+singhamPDF 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_off0000b659.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB659 10460 bytes
SHA-256: a542cb90dd18e0eace6c7d51eb24a9b35545866e63323278094611238a93784e
font_01_sfnt_off0000cde3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDE3 16180 bytes
SHA-256: 0f9a4c9c167284f9f00c7f1aa87d59ba0b115dec284612d9ee7137b9a01faff2
font_02_sfnt_off0000f794.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF794 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1