Malicious PDF — malware analysis report

Static analysis result for SHA-256 9fa77e58dde4ab50…

MALICIOUS

PDF

73.2 KB Created: 2021-09-19 00:53:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 9d78b12a9a2d69348eb48c7e62e41a3a SHA-1: 6c103b3d84130a6bab5d3ae954628def74e44548 SHA-256: 9fa77e58dde4ab50d6f249aedd91a506a49dd48b8132c71777f165155269ad7f
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains numerous embedded URLs, many of which point to PDF files hosted on various domains, indicating a link farm or redirection strategy. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests this is a tactic to obscure malicious intent or distribute further payloads. No scripts were extracted, but the PDF structure itself is used to host and link to potentially malicious content.

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://vallovin.it/userfiles/files/pozifovezere.pdf In PDF document text
    • https://chulintemple.house-well.com/CKEdit/upload/files/29966218285.pdfIn PDF document text
    • http://bagliodeimille.it/userfiles/files/sepajakirinoza.pdfIn PDF document text
    • https://suncables.co/images/file/zopisek.pdfIn PDF document text
    • https://gogreenonline.net/userfiles/image/fckeditor/file/12344469443.pdfIn PDF document text
    • https://ijaetis.org/ckfinder/userfiles/files/wopubosajo.pdfIn PDF document text
    • https://www.lavishlook.se/wp-content/plugins/super-forms/uploads/php/files/50070040b3921f266b8691e61ca70b31/22445002659.pdfIn PDF document text
    • http://devison-matras.com/upload/file/zosukaniji.pdfIn PDF document text
    • https://kluchar.net/klucharnet/images/file/45739559991.pdfIn PDF document text
    • http://www.biharikft.hu/bihari-admin/ckfinder/userfiles/files/xaselinalebakulizepale.pdfIn PDF document text
    • https://www.funes.gob.ar/ckfinder/userfiles/files/39422108608.pdfIn PDF document text
    • http://tomgiongvip.com/uploads/files/file/46236590128.pdfIn PDF document text
    • http://hstairan.com/FCKeditor/editor/filemanager/connectors/php/userfiles/file/58597338457.pdfIn PDF document text
    • https://www.taxikladis.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1613696cfe2455---xevozaresazon.pdfIn PDF document text
    • http://kite-surf.sk/files/betazex.pdfIn PDF document text
    • http://clairerolo.com/userfiles/file/38205702352.pdfIn PDF document text
    • https://needletherapy.eu/upload/file/xurerewaberizefa.pdfIn PDF document text
    • https://nurea.se/currency/userfiles/file/fotusesogefojudesez.pdfIn PDF document text
    • http://unitez.net/images/newtech/files/zapojas.pdfIn PDF document text
    • http://aokisuper.com/ckfinder/userfiles/files/rudamuxosixivaxo.pdfIn PDF document text
    • http://usaoxin.com/userfiles/2021-9/file/ketejisawuri.pdfIn PDF document text
    • http://hyswimpool.com/userfiles/kukufagapumurevumumakepi.pdfIn PDF document text
    • http://archiw.gbpopatowiec.pl/img/upload/files/bafamutirufasuwidogav.pdfIn PDF document text
    • http://tt-ural.su/admin/ckfinder/userfiles/files/tifodonemaruzo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=urgent+dua+for+healthPDF 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_off0000b560.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB560 20064 bytes
SHA-256: 2e3871da56cd2c93ccd31f8d8d5190710b6f25bf8787245839470238c534202f
font_01_sfnt_off0000e87e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE87E 10480 bytes
SHA-256: 5af3d625892414ab5e54ab0f005d2e5c2c0f9087017d22248a6a446e07be03c1
font_02_sfnt_off00010001.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10001 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1