Malicious PDF — malware analysis report

Static analysis result for SHA-256 a71251b8de58a081…

MALICIOUS

PDF

76.2 KB Created: 2021-10-05 00:44:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 3f0c2c1816864c6b058fc25f5e4a982c SHA-1: 3d076d43ec607e9ce842dcf3b37d15d4cd0fef42 SHA-256: a71251b8de58a08143be134fa6e0a6ded500b80ce9e244effce8d73593cc1ea4
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was identified as malicious by ClamAV and an ML classifier, with multiple heuristics indicating it functions as a link farm. The PDF contains numerous embedded URLs pointing to various domains, suggesting an attempt to redirect users to potentially malicious content or phishing sites. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic specifically flags the document as a non-clustered link farm on disposable hosting, reinforcing the malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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 https://archism.ru/uplcv?utm_term=power+cut+in+my+area+today PDF link annotation
    • http://duepassidalcentro.it/userfiles/files/19749299763.pdfIn PDF document text
    • http://makassitools.com/userfiles/file///gibuwudadafatuzefowunez.pdfIn PDF document text
    • https://svltv.in/userfiles/files/modelokegigebisubu.pdfIn PDF document text
    • http://ayrh.internet-match.com/upload/files/suvelikulisefapivu.pdfIn PDF document text
    • http://agisinfo.ru/uploads/content/files/xuniramawugomumadid.pdfIn PDF document text
    • http://sungwoo-n.com/userfiles/file/jopoxozebezofef.pdfIn PDF document text
    • https://igruppe.no/ckfinder/userfiles/files/xapunofusu.pdfIn PDF document text
    • http://ilonew.tasksplan.com/ckfinder/userfiles/files/maguwalulodawabefabiruk.pdfIn PDF document text
    • http://gabinetpro.gabinetpro.pl/kosmetyczka/krakow/files/52617710669.pdfIn PDF document text
    • http://watch62.ru/files/files/55424269328.pdfIn PDF document text
    • http://immodraft.de/images/architekten_agentur_images_/file/vogenomaxagako.pdfIn PDF document text
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161474a3e716d1---jigemejo.pdfIn PDF document text
    • http://bukvoznaika.ru/ckfinder/userfiles/files/54681340671.pdfIn PDF document text
    • https://vozilasavozacem.rs/files/93200861772.pdfIn PDF document text
    • https://marcvandewiele.com/userfiles/file/10559448186.pdfIn PDF document text
    • http://jmvlpslimited.com/ci/userfiles/files/44638681856.pdfIn PDF document text
    • http://mtecommerce.it/public/news/file/pabiw.pdfIn PDF document text
    • http://accessiblevehicleservices.com/userfiles/file/25118344603.pdfIn PDF document text
    • http://3mfa.com/images/editor/files/35550047017.pdfIn PDF document text
    • http://iltorg.ru/upload/file/xufonodaxudubokamojir.pdfIn PDF document text
    • https://marksiegeldds.com/wp-content/plugins/super-forms/uploads/php/files/e75ffc37d108db1e0a3a97958f446c2f/84206272815.pdfIn PDF document text
    • http://2018.letnifestiwal.pl/ckfinder/userfiles/files/jemekepatox.pdfIn PDF document text
    • http://topspeed4wd.com/ckfinder/userfiles/files/57832323522.pdfIn PDF document text
    • 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_off0000c6a3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6A3 10620 bytes
SHA-256: 30157b72ffb18cf8fdbfd3536c60751ef3b3cd77182d88489f753cf79f7cf5c7
font_01_sfnt_off0000defc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEFC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f70e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF70E 17076 bytes
SHA-256: 01efd97ffa2b4b025757c8e65cd9cebf00069c7817502d64a48fcd3c7a8e3edb