Malicious PDF — malware analysis report

Static analysis result for SHA-256 d606f985c12765cc…

MALICIOUS

PDF

71.3 KB Created: 2021-09-26 10:20:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 2e89b001d1cfef80af65f658393d451f SHA-1: 833b4f15e42c065511cc9a6e91c91b6b4f631e65 SHA-256: d606f985c12765cc7daa14f7f760e68cb55e149f99807c732826d1b833361957
126 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, with one heuristic identifying it as a link farm on disposable hosting. The primary purpose appears to be directing users to a collection of other PDF files hosted on various domains, potentially for SEO poisoning or to serve as a distribution point for further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 http://vaonhaphatphap.com/images/uploads/files/14328779783.pdf In PDF document text
    • http://h-p-n.fr/catalogue_dynamique/file/pavijusatipe.pdfIn PDF document text
    • http://costruzionibulagna.it/userfiles/files/bevizazamunej.pdfIn PDF document text
    • https://samsungklima.net/upload/ckfinder/files/panijojuxabirawalujuwen.pdfIn PDF document text
    • http://luckdidea.com/ckfinder/images_store/files/10414888179.pdfIn PDF document text
    • http://tinavaron.com/ckfinder/userfiles/files/74673265360.pdfIn PDF document text
    • https://grandiosieventinuziali.it/filesUploads/file/93868191063.pdfIn PDF document text
    • https://igraonica.me/userfiles/file/turagi.pdfIn PDF document text
    • http://stlukesfp.org/ckfinder/userfiles/files/sepaxemawoguwokogujifojaj.pdfIn PDF document text
    • https://xn--fct5g39pjpo.tw/upload/leakstop/files/46758432998.pdfIn PDF document text
    • http://0975811252cool.linker.tw/files/popimibadinirimisalesug.pdfIn PDF document text
    • http://rebornfair.com/FileData/ckfinder/files/20210922_FB171496DB6F2B4E.pdfIn PDF document text
    • http://przedszkolenisko.pl/userfiles/file/19979527942.pdfIn PDF document text
    • http://greenbiotech.vn/uploads/userfiles/file/137650620.pdfIn PDF document text
    • https://srmhomes.com/images/bulk_images/files/68821343917.pdfIn PDF document text
    • http://ximangsongthao.com.vn/app/webroot/uploads/files/tumusosorumurigimimewev.pdfIn PDF document text
    • http://congtyvima.com/images/Download/9870513671.pdfIn PDF document text
    • http://darec.sk/files/files/tedosetepegipenelidowokem.pdfIn PDF document text
    • https://mahae.hu/files/files/xovetajetutipilexajiweri.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/5f58191c38c2f1b2d5a793bdfd173e1a/gikaxidigugapenake.pdfIn PDF document text
    • https://cqhuaan.myhost360.cn/upload/files/09-04-06-31-32-21.pdfIn PDF document text
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614eb28ab8d34---87751073453.pdfIn PDF document text
    • https://korzayithalat.com/spot/admin/fckeditor/userfiles/file/zopuviwajugalixobebag.pdfIn PDF document text
    • http://foto-klub.dk/userfiles/file/rivolebonesuve.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=kissasian+high+quality+dramaPDF 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_off0000b314.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB314 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cb26.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB26 17548 bytes
SHA-256: e4f9512b825a1a4838789ece8aa2dc9385e5faadd92ccb2918e686c62534fdf8
font_02_sfnt_off0000f7af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7AF 10792 bytes
SHA-256: fb64e39528b25d15f292e46d38b94cb5a9e1a2705196ffcbcd3e09f0b35072b4