Malicious PDF — malware analysis report

Static analysis result for SHA-256 636a35e7e86fb4df…

MALICIOUS

PDF

74.2 KB Created: 2021-10-07 16:23:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 9428eb72fe2cd4f518e19b743f4a7c18 SHA-1: 62b8c34e3d2c827487af9a7428fbb5100a21ecca SHA-256: 636a35e7e86fb4df788e1c42b82b391374a4ca5b8256448be63001d21579e94f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and ML classifiers indicated a high probability of maliciousness. The PDF contains numerous embedded URLs, many pointing to PDF files on various domains, suggesting a link farm or redirection mechanism. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports the idea that the PDF is used to host a collection of links, likely for malicious purposes such as phishing or distributing further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/1612fd17c7704a---tarakegijoweli.pdf In PDF document text
    • https://heritran.vn/uploads/news_file/wukavud.pdfIn PDF document text
    • http://mamitobe.ru/files/file/xadisijewamado.pdfIn PDF document text
    • http://langeline.com/ckeditor/upload/files/58941163403.pdfIn PDF document text
    • https://prokoncept.hu/admin/blogfck/image/file/zivugekipurezix.pdfIn PDF document text
    • http://beloezoloto.ru/userfiles/file/soxodalixemezarope.pdfIn PDF document text
    • https://widerbet.pl/userfiles/file/4069716328.pdfIn PDF document text
    • https://ou-ravda.com/ckfinder/userfiles/files/xojarusakifuwado.pdfIn PDF document text
    • https://accu-split.com/userfiles/files/68430446793.pdfIn PDF document text
    • https://polresseluma.com/assets/ckfinder/core/connector/php/uploads/files/lufenimurozagotidines.pdfIn PDF document text
    • http://tootingtaxi.com/survey/userfiles/files/5576625538.pdfIn PDF document text
    • http://alrabbancapital.com/file/files/65534215243.pdfIn PDF document text
    • https://bhandarisurgical.com/ckfinder/userfiles/files/68386168811.pdfIn PDF document text
    • https://nothingbutsafetyglasses.com/userfiles/file/jedawazorad.pdfIn PDF document text
    • http://www.gamylai.vn/uploads/files/44282831845.pdfIn PDF document text
    • http://dblbtech.com/userfiles/file/kunixaruketud.pdfIn PDF document text
    • https://h016s5or78-du3.com/contents/files/tazekizopiribabixo.pdfIn PDF document text
    • http://pathtojanna.com/userfiles/files/lamanukajakigotivikajuk.pdfIn PDF document text
    • http://phdpecs.hu/userfiles/files/92338357279.pdfIn PDF document text
    • http://the100voicesofgospel.ch/fichiers/newsletter/file/74932562580.pdfIn PDF document text
    • https://pernambucoimortal.com/imagens/files/kaxosomunoxovukemafuwe.pdfIn PDF document text
    • http://bratislava.topenglish.sk/app/webroot/gallery/files/kusoruxisafaxifapux.pdfIn PDF document text
    • https://habibitours.org/ckfinder/userfiles/files/diliravo.pdfIn PDF document text
    • http://gro-felix.si/uploads/4255703305.pdfIn PDF document text
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files/mexukilazepawome.pdfIn PDF document text
    • http://worldsocialistpartyindia.org/ckfinder/userfiles/files/10121254946.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=3+letter+words+with+iPDF 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_off0000bf97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF97 17028 bytes
SHA-256: 75c6d2c0d996342a72de973e784680fd8d4c3c12ff6f89236dc17ae43b61ef7c
font_01_sfnt_off0000ebf2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBF2 10240 bytes
SHA-256: e90482e762e331d9df522910144f1959255a64948e754ea177a7e934ee49b979
font_02_sfnt_off00010322.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10322 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1