Malicious PDF — malware analysis report

Static analysis result for SHA-256 a7a7842a0d2d19ad…

MALICIOUS

PDF

70.8 KB Created: 2021-09-18 19:35:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 5a1e1813c3e2e479c9a98b0212cbc418 SHA-1: b5955f14eb34486c7dfb75313a783543e31a0c50 SHA-256: a7a7842a0d2d19ad7e32073bb4899d1e0081ffc977d2b08654e35f7285f6fa95
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which are part of a link farm hosted on disposable domains, suggesting an attempt to obscure the final malicious destination. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using small PDFs as link farms on disposable hosting, further supporting a phishing or malware distribution motive.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://coretry.ru/uplcv?utm_term=game+hp+android+download PDF link annotation
    • https://www.hkha.com.hk/ckfinder/userfiles/files/71920055628.pdfIn PDF document text
    • http://soojuspilt.ee/files/file/muvupebibede.pdfIn PDF document text
    • https://fultoys.com/userfiles/zuwukigi.pdfIn PDF document text
    • https://strategie-forex.com/ckfinder/userfiles/files/jobosalemanenadokux.pdfIn PDF document text
    • http://stowarzyszeniemalyksiaze.eu/img/upload/files/63673508146.pdfIn PDF document text
    • http://ctkupavna.ru/upload/file/ridagixudipereluzurinona.pdfIn PDF document text
    • https://konchris.com/userfiles/file/1631761630.pdfIn PDF document text
    • http://ozt.zielonetarasy-cieplice.pl/uploads/userfiles/files/56829667822.pdfIn PDF document text
    • https://silverbirdmarketing.com/pages/images/file/ruzuj.pdfIn PDF document text
    • http://investinwielkopolska.pl/application/lib/ckfinder/userfiles/files/simomujelemetenor.pdfIn PDF document text
    • http://topspeed4wd.com/ckfinder/userfiles/files/diduxaduzudogej.pdfIn PDF document text
    • http://ticketsperiodico.com/galeria/files/lutijenebuja.pdfIn PDF document text
    • http://csc0451.com/userfiles/file/20210904205347_ia5yao.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/16131732cbe230---vajadi.pdfIn PDF document text
    • https://aathichudi.org/userfiles/file/85124163670.pdfIn PDF document text
    • http://solarhomepage.ch/fckeditor/editor/images/file/44197676300.pdfIn PDF document text
    • http://veterinariogiardinelli.it/userfiles/files/84357726267.pdfIn PDF document text
    • http://wahluenfty.com/userfiles/zuxituvu.pdfIn PDF document text
    • https://detector-billetes.com/Imagenes/file/juloketozas.pdfIn PDF document text
    • http://kanchanaspa.com/ckfinder/userfiles/files/rirul.pdfIn PDF document text
    • http://prplus4u.com/ckupload/files/29842643025.pdfIn PDF document text
    • http://kitpaisal.com/mypicture/file/firifi.pdfIn PDF document text
    • http://benthanhsgfarm.net/images/uploads/files/50816138591.pdfIn PDF document text
    • https://luxurytravel-show.com/wp-content/plugins/super-forms/uploads/php/files/56e33a2e89a0fc7d43871f6a5e5ef7c9/poganofanewibuvapaki.pdfIn PDF document text
    • http://learningkey.org/userfiles/nubuvuwosop.pdfIn PDF document text
    • 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_off0000b7c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB7C3 14976 bytes
SHA-256: dca82749087c80fee3032d7b555a2643019aaa5fbd61ea392bdd173661a57057
font_01_sfnt_off0000dda5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDA5 10516 bytes
SHA-256: c066806c03f063c53d55c55faa9154c1b4699e92288ea3ff4352160c4e2ae4a1
font_02_sfnt_off0000f558.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF558 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1