Malicious PDF — malware analysis report

Static analysis result for SHA-256 e9a8cbab2d8a63e8…

MALICIOUS

PDF

99.4 KB Created: 2021-09-18 22:26:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: acc5fac0dc0e50dd9899742a7d6627c2 SHA-1: ccfdaa6c0b79a8c33f3b67a7bd0bb68fb39b2c3f SHA-256: e9a8cbab2d8a63e8cca0641d79cd6c199417fbd01e04e0c7c1cc840010cf1590
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on disposable domains and appear to be part of a link farm. The heuristic 'PDF_RANDOM_URL_LINK' and 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggest malicious intent, likely for phishing or distributing further malware. The ClamAV detection and ML classifier further support the malicious classification.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9936

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://ketchas.ru/uplcv?utm_term=dragon+ball+z+kai+the+final+chapters+dub PDF link annotation
    • http://congtyvima.com/images/Download/vejulozogexamukizosomesen.pdfIn PDF document text
    • http://vitalbafitnessclub.eu/userfiles/files/nifipe.pdfIn PDF document text
    • https://jmbarrenetxea.soinuenea.eus/files/galeria/files/42136752997.pdfIn PDF document text
    • http://leprofit.ee/cmsfile/contentfiles/zorubalodabida.pdfIn PDF document text
    • https://www.jakketoes.be/ckfinder/userfiles/files/xijofivogozuzaluniru.pdfIn PDF document text
    • http://witnesstherealist.com/wp-content/plugins/super-forms/uploads/php/files/5331be00012ba36e3ec76782d4a04ec0/57333036627.pdfIn PDF document text
    • https://gitteszoneklinik.dk/ckfinder/userfiles/files/tenanabitigesalab.pdfIn PDF document text
    • http://cobmedia.hu/include/35392130739.pdfIn PDF document text
    • http://preiss.at/upload_files/files/xadiberiwoxerisisetafi.pdfIn PDF document text
    • https://blsautomation.com/ckfinder/userfiles/files/6391262874.pdfIn PDF document text
    • http://inruho.ru/ckfinder/userfiles/files/44559863132.pdfIn PDF document text
    • https://hobbypet.cz/files/file/59019577722.pdfIn PDF document text
    • http://studiotecnicopinto.it/userfiles/files/94207962517.pdfIn PDF document text
    • https://biharlokmanch.org/userfiles/file/pijisodowesolaja.pdfIn PDF document text
    • http://savalis.ru/userfiles/file/76783926660.pdfIn PDF document text
    • http://veiligheidssloten.nl/ckfinder/userfiles/files/73912452566.pdfIn PDF document text
    • https://iqrainternationalschool.org/_assets/files/6472838793.pdfIn PDF document text
    • http://4bx.pl/public/file/tuwenewopixurifibewoxun.pdfIn PDF document text
    • http://ambulatorioveterinarioilghirlandaio.it/userfiles/files/47302442317.pdfIn PDF document text
    • http://www.dr.schure.net/ckfinder/userfiles/files/gebewiwovujopuxu.pdfIn PDF document text
    • https://voolabs.com/wp-content/plugins/formcraft/file-upload/server/content/files/161378a8baa4ed---589857719.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/16136be7cdab48---xixojurabuweti.pdfIn PDF document text
    • http://opuspointpartners.com/ckfinder/userfiles/files/11255840326.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_off000121c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121C8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000139df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139DF 11292 bytes
SHA-256: 66b3e750e164e8b53e9a4b64d7a8ea08c192f40873a276d21e43e3b471b2879e
font_02_sfnt_off000153f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x153F5 17228 bytes
SHA-256: 3e9eb5b9f73f84a0efaba184f5c287e86913879a21ed8eecc67b7bf9d6c540ed