Malicious PDF — malware analysis report

Static analysis result for SHA-256 4ca1d362af50a212…

MALICIOUS

PDF

81.5 KB Created: 2021-10-09 23:49:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 27ad0109977ce6c2df7f649d768c85ad SHA-1: 994139981f5fb86cccce00e95116f26d1fc2a14d SHA-256: 4ca1d362af50a2128f8a1b8beaafeef0dfff036f78744b04b1653b779799fd49
126 Risk Score

Malware Insights

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

The PDF file was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests the document's primary purpose is to host a large number of links pointing to other PDFs, likely for SEO manipulation or to distribute further malicious content. The embedded URLs, while many are benign, include several unknown domains that could serve as part of this link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://ezclasssites.com/var/wwww/dev-ezclasssites-com/data/files/97653423745.pdf In PDF document text
    • https://mr-alian.com/upload/ckfinder/files/47750441050.pdfIn PDF document text
    • https://grupahatak.pl/admin/_fck_files/file/vabilisanekomifesifov.pdfIn PDF document text
    • http://braintradingbcn.com/wp-content/plugins/super-forms/uploads/php/files/2157b4aaae65bac630e4f4555e0c86ce/68541317783.pdfIn PDF document text
    • https://thefertilizergranulators.com/d/files/65334305546.pdfIn PDF document text
    • https://pinkrali.com/calisma2/files/uploads/mojekizo.pdfIn PDF document text
    • http://xn--djr00fsyfv0o5qgy9u.net/filespath/files/20210927185343.pdfIn PDF document text
    • http://startent.ru/SITE/files/editor/file/misuzikelileporatijazuxoj.pdfIn PDF document text
    • http://architettosirocco.it/userfiles/files/44434162815.pdfIn PDF document text
    • http://stepasidemedical.com/images/uploads/file/98506067043.pdfIn PDF document text
    • http://shahnawazonline.com/uploads/files/lozonuduwaxituvovizokizip.pdfIn PDF document text
    • http://c2ctrading.org/cms_upload/files/8975944209.pdfIn PDF document text
    • http://slavutich-media.ru/userfiles/file/61577007445.pdfIn PDF document text
    • https://realxenon.ru/uploads/files/92018997728.pdfIn PDF document text
    • http://swotaweb.com/img/upload/file/51815838616.pdfIn PDF document text
    • http://dfzh.jmdftour.com/fckeditor/userimages/file/gisefaz.pdfIn PDF document text
    • https://ikitellirezistans.com/upload/files/lutuz.pdfIn PDF document text
    • http://www.barbazan-debat.fr/ckfinder/userfiles/files/muniboporim.pdfIn PDF document text
    • http://travelspace.pl/userfiles/file/38662216463.pdfIn PDF document text
    • http://vektor-bezpeki.com/userfiles/files/68191298033.pdfIn PDF document text
    • http://carrozzeriabosini.net/userfiles/files/17603991541.pdfIn PDF document text
    • https://clubsecurite.fr/webroot/upload/files/vitun.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=give+examples+of+sole+proprietorshipPDF 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_off0000dada.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDADA 10724 bytes
SHA-256: f9487af988e93306c713c883a435f332bd35d7a43c41d0b48e531982ac38e273
font_01_sfnt_off0000f38c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF38C 17384 bytes
SHA-256: 6dfe186e790125ac79ed9b9ea07ce69eb7f92074aeedc2f285caab28fe1cccf5
font_02_sfnt_off00012039.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12039 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1