Malicious PDF — malware analysis report

Static analysis result for SHA-256 2533bdb042a27623…

MALICIOUS

PDF

83.6 KB Created: 2021-09-10 21:53:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 111133d84b2c362152fc36331c08a8e2 SHA-1: 227614e3474e393930e2937c363ee25b8aa58940 SHA-256: 2533bdb042a27623011efddcb7d9098ded9def982f29b0c40cab08f8f011a055
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs pointing to other PDF files, suggesting a link farm or distribution mechanism. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for these links, likely to evade detection or for SEO manipulation. No scripts were extracted, but the overall structure points to a malicious document intended to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://uniquehotelsolutions.com/files/others/63298289555.pdf In PDF document text
    • http://thomas-zigon.de/images/file/purelaxo.pdfIn PDF document text
    • http://busangh.com/attfile/fckimg/file///2021091045150_315292360.pdfIn PDF document text
    • http://packturf.fr/files/83613314642.pdfIn PDF document text
    • http://webinaris.eu/ckfinder/userfiles/publics/files/73014829167.pdfIn PDF document text
    • http://wienbildarchiv.com/upload_files/files/rotorovizezawetevud.pdfIn PDF document text
    • http://dzirerealtors.com/uploads/jajafo.pdfIn PDF document text
    • http://lindseyderence.com/userfiles/files/24160844582.pdfIn PDF document text
    • http://maschimaurizio.it/userfiles/files/24211417351.pdfIn PDF document text
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/7qg47dofke8u5crl55tupfj811/petisuzezozanogodenodu.pdfIn PDF document text
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161385c1505c00---83818993838.pdfIn PDF document text
    • http://nhasachthunam.com/upload/files/91056178309.pdfIn PDF document text
    • http://feuerwehr-mittenwalde.de/mediathek/files/4043607510.pdfIn PDF document text
    • https://htapigroup3.com/contents/files/tovedagelesazivalurof.pdfIn PDF document text
    • http://protectakoteasia.com/ckfinder/userfiles/files/4708334661.pdfIn PDF document text
    • https://urology-andrology.com/userfiles/file/gadozin.pdfIn PDF document text
    • https://ip-kamera-rendszer.hu/ckfinder/userfiles/files/64436036263.pdfIn PDF document text
    • http://riccaassociati.eu/userfiles/files/6747204222.pdfIn PDF document text
    • https://oilbasaro.com/web/images/ckfinder/files/20210901225820.pdfIn PDF document text
    • http://shtaket46.ru/page_edit/_samples/userfiles/files/sovaxenirebedivegor.pdfIn PDF document text
    • http://aczelzalog.hu/tmp/zovojaluzemejobemiwotoxug.pdfIn PDF document text
    • http://yacpa.org/yacpafiles/file/56833464365.pdfIn PDF document text
    • https://tonwen.org/userfiles/file/navavefinojunilemizu.pdfIn PDF document text
    • http://www.feniuniversity.edu.bd/app/webroot/ckfinder/userfiles/files/98421064689.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=el+siete+machos+pelicula+completa+en+espa%C3%B1ol+latinoPDF 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_off0000d9d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9D3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f1e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1E5 20612 bytes
SHA-256: b4b87625ca55a8e745cf78fecae7113178e526be2627f2633b81ef3fddb39716
font_02_sfnt_off000126b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x126B5 10828 bytes
SHA-256: feb8668e3b67874ab83f453779d4e33a1f185321d9165ec363034d8ea0c15077