Malicious PDF — malware analysis report

Static analysis result for SHA-256 a44733b2ab2eb2a1…

MALICIOUS

PDF

87.3 KB Created: 2021-09-11 12:17:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: d1d49b09855902034eada10ac194e063 SHA-1: da7d0cf7a16adfc7c128270f24a1b4d0b94352da SHA-256: a44733b2ab2eb2a10747a4ad4e1432b792c303528b5391a1f1b3107de78b33f8
126 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as a phishing trojan and a machine learning classifier indicated a high probability of maliciousness. The heuristics indicate the PDF acts as a link farm, containing numerous links to disposable domains, with one specific URL identified as a potential entry point. The document body is heavily obfuscated and unreadable, suggesting it is not intended for direct user interaction but rather to facilitate the malicious redirection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://tropo-design.com/ckfinder/userfiles/files/20470342891.pdf In PDF document text
    • http://www.grupoaccs.net/ckfinder/userfiles/files/6872716859.pdfIn PDF document text
    • http://skogsformedling.se/bilder_umeny/File/madigarorepasaxigatadu.pdfIn PDF document text
    • http://loscogliodifavignana.it/userfiles/files/40341627873.pdfIn PDF document text
    • http://granitemountainranch.net/userimages/rasufebajesirakogikeguriv.pdfIn PDF document text
    • https://beautydent.hu/editor_up/35853642705.pdfIn PDF document text
    • http://antoniolescio.net/userfiles/files/bujivonurunuwoxa.pdfIn PDF document text
    • http://kppzp.pl/userfiles/file/82502215036.pdfIn PDF document text
    • http://n2nnetworks.com/files/others/37815660919.pdfIn PDF document text
    • http://www.gonouvellezelande.com/files/vixoguwolawikagajik.pdfIn PDF document text
    • https://profitaler.com/UserFiles/file/79666320968.pdfIn PDF document text
    • https://md-bud.pl/szklo/photos/file/vosoromitibivefod.pdfIn PDF document text
    • https://mysilo.com/upload/ckfinder/files/luzun.pdfIn PDF document text
    • http://a-range.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613260edc25fe---robuwobinive.pdfIn PDF document text
    • http://www.mezmat.ru/ckfinder/userfiles/files/86956621719.pdfIn PDF document text
    • http://tuecpa.com/file_media/file_image/file/16735638387.pdfIn PDF document text
    • http://myphamasia.net/upload/files/62235642220.pdfIn PDF document text
    • https://implant-drill.com/userfiles/file/gafofapelel.pdfIn PDF document text
    • http://dokumsuzgec.com/userfiles/files/segisufokapagapufupasutad.pdfIn PDF document text
    • http://areawifi.com/DESARROLLO/userfiles/files/79643069592.pdfIn PDF document text
    • https://sieuthimayphat.com/ckfinder/userfiles/files/zaxojoza.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=how+to+transfer+messages+to+new+androidPDF 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_off0000f05c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF05C 10728 bytes
SHA-256: 06810bc2ecb28f6944e2e4d19014d09210af558ef38012fb04de01428ba01bef
font_01_sfnt_off000108d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108D1 17968 bytes
SHA-256: d69a0ddf48562d675696c7bc880411642d2613d3e27f40bbd950b1dc4fc4aa07
font_02_sfnt_off00013759.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13759 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1