Malicious PDF — malware analysis report

Static analysis result for SHA-256 4add5504f6bd8df4…

MALICIOUS

PDF

74.8 KB Created: 2021-09-19 11:53:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 3ae99a326930ad94fe00dd2e63cfe339 SHA-1: bc18a52622ffdba591155985c01f78c2371cd6f1 SHA-256: 4add5504f6bd8df405c2de652633b4481c05b376d2124019afa4ff2780d0e385
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to external websites, many of which are hosted on compromised or disposable domains, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with phishing and malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://synerhu.ru/uplcv?utm_term=simple+and+compound+probability+worksheet+answers+pdf PDF link annotation
    • http://ginzaramen.us/uploads/files/fapapenorufizosadamelu.pdfIn PDF document text
    • https://rybczewice.pl/userfiles/file/gakusotu.pdfIn PDF document text
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/161373ec47f41f---zaripipakigonup.pdfIn PDF document text
    • http://abwwilson.com/uploads/files/966590820.pdfIn PDF document text
    • https://www.grandeprairie.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613b7510f1c1b---gibevatalizajoba.pdfIn PDF document text
    • https://hopclickhospitality.com/scgtest/team-explore/uploads/files/5090489526.pdfIn PDF document text
    • http://scea.edu.mn/ckfinder/userfiles/files/wotovivifi.pdfIn PDF document text
    • https://zhavezbozi.cz/data/file/92211810392.pdfIn PDF document text
    • https://activepymes.com/pub/file/76953352134.pdfIn PDF document text
    • https://samirkumarpaul.com/ckfinder/userfiles/files/pejowomuki.pdfIn PDF document text
    • http://concilianavarra.com/userfiles/files/77441749133.pdfIn PDF document text
    • https://fidelishospice.com/ckfinder/userfiles/files/dusitub.pdfIn PDF document text
    • http://80tner.netsociality.com/upload/files/zasakekabomalilu.pdfIn PDF document text
    • https://adverto.ee/userfiles/file/xijuvojoponelus.pdfIn PDF document text
    • https://ngusacdon.com/upload/files/nizezosupov.pdfIn PDF document text
    • https://ghadir-eng.com/userfiles/files/94596566759.pdfIn PDF document text
    • http://gmei.lt/ckfinder/userfiles/files/36988942166.pdfIn PDF document text
    • https://www.taxikladis.gr/wp-content/plugins/formcraft/file-upload/server/content/files/1613be546e7f32---gularozonetemijaxiw.pdfIn PDF document text
    • https://bulendengin.com/upload/ckfinder/files/76064095037.pdfIn PDF document text
    • http://onelove.cz/file/kebokisuru.pdfIn PDF document text
    • https://tavio.ru/files/file/jemiwexubovid.pdfIn PDF document text
    • http://dichvutot99.com/webroot/img/files/subomovalel.pdfIn PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/161466041e2c6c---wonozovunin.pdfIn PDF document text
    • http://www.recko.ru/ckfinder/userfiles/files/60919767903.pdfIn PDF document text
    • https://polytex.de/sites/default/files/kirerarikisuz.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://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_off0000c024.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC024 11492 bytes
SHA-256: f522adb6c3c8c0ff2b4366e5380d8dae3b2a484bfd11e4f229b68605c8e7ced2
font_01_sfnt_off0000daf3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAF3 17700 bytes
SHA-256: 95fe6ad938e6c5d1f7d47ccabd2f3fdc8e365e67e43e8bea5f7a731ed8049075
font_02_sfnt_off00010933.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10933 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1