Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8b0856c69ea5d87…

MALICIOUS

PDF

86.8 KB Created: 2021-09-16 00:30:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 3a4015b565eb2fc87de76d889efc4b2c SHA-1: 7a869bb74c3f73e5770bdd4e9ca452c6b71e76f4 SHA-256: c8b0856c69ea5d873bde0afc0308c24ed2ac7b60f005436741592a27373207f1
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which are hosted on domains that appear to be part of a link farm, as indicated by the PDF_SEO_DISPOSABLE_LINK_FARM heuristic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. While no scripts were explicitly extracted, the PDF structure and embedded links are indicative of an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://www.grundys.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613f9fe2cf341---refamidawakirujeduvom.pdf In PDF document text
    • https://www.champagne-cornevin.fr/ckfinder/userfiles/files/wizaregigobetativofosid.pdfIn PDF document text
    • https://bandai-k.com/userfiles/file/taliderulu.pdfIn PDF document text
    • http://fitnessklub-impuls.pl/uploads/assets/file/90032983662.pdfIn PDF document text
    • http://webinaris.training/ckfinder/userfiles/publics/files/83037194094.pdfIn PDF document text
    • http://prvugkh.ru/uploads/files/gijofowixegowanene.pdfIn PDF document text
    • https://univerosg.com/ckfinder/userfiles/files/rewuwegov.pdfIn PDF document text
    • http://ulv-fogger.es/d/files/xudoxefuvaroxivetulozig.pdfIn PDF document text
    • https://dwitunggaljaya.com/sitefiles/file/namen.pdfIn PDF document text
    • https://www.hosotte.com/ckfinder/userfiles/files/5982844796.pdfIn PDF document text
    • https://izyskately.ru/foto/ck/files/60695634093.pdfIn PDF document text
    • http://ms-krmelin.cz/app/webroot/files/files/zadixopapakum.pdfIn PDF document text
    • https://tomaszbizon.tomaszbizon.pl/web/uploads/files/mudopaxikiwata.pdfIn PDF document text
    • https://nezrenpin.com/calisma2/files/uploads/tubavaj.pdfIn PDF document text
    • https://flavio-tonon.it/public/file/wozapadatisisugojal.pdfIn PDF document text
    • http://camberwelltaxi.com/survey/userfiles/files/xakojedukagesojagelajaz.pdfIn PDF document text
    • http://jyotiacademicpress.org/uploads/file/daxividujuzuronid.pdfIn PDF document text
    • http://mindentudor.hu/userfiles/file/44084443115.pdfIn PDF document text
    • https://volnynaklad.cz/data/file/99862001585.pdfIn PDF document text
    • http://clinicaveterinariamontecchia.com/userfiles/files/suzanixajotiwevatimul.pdfIn PDF document text
    • https://fairtradeportal.pl/userfiles/file/radezaku.pdfIn PDF document text
    • http://childconnect.com/swi/fckfiles/file/34185698145.pdfIn PDF document text
    • https://grupa-energia.pl/attachments/file/31832153901.pdfIn PDF document text
    • https://palet-school.com/files/files/9578503825.pdfIn PDF document text
    • http://agppi99.pretty-match.com/upload/files/29260768659.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=hale+bopp+comet+1997PDF 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_off0000ec27.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC27 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010439.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10439 19524 bytes
SHA-256: d4fd88b7c37e43d756fdaf3bb72ee7ccdf41882d682f03df92478aee7eff3698
font_02_sfnt_off00013600.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13600 10472 bytes
SHA-256: 4ac409f3d6342d9f7bd75bddc3d238a711a791eb89d309a0026677fe38ae5a39