Malicious PDF — malware analysis report

Static analysis result for SHA-256 f3ed728a74405ff5…

MALICIOUS

PDF

74.2 KB Created: 2021-09-24 11:55:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 5924dfc1cc0387db798ae08e7485d029 SHA-1: 6c2509e1e9b4d7f0730bb271f2fec705495b9d64 SHA-256: f3ed728a74405ff54b9cca5fc024950dd702ac71b074f8296935036b21aa615d
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, indicating it's a phishing or trojan PDF. It contains numerous external links, many pointing to compromised websites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a non-clustered link farm on disposable hosting. No scripts were extracted, but the primary attack pattern involves directing users to external, potentially harmful, URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://coretry.ru/uplcv?utm_term=best+shooting+video+games PDF link annotation
    • https://www.bmo-agencement.fr/ckfinder/userfiles/files/4665469312.pdfIn PDF document text
    • https://fortlauderdale-carservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613840770de40---xejasiguzarif.pdfIn PDF document text
    • https://zenit-npk.ru/files/file/zolupunodunabuxevogalo.pdfIn PDF document text
    • http://shendaoguoji.com/data/attachment/file/goforitupanizadonevu.pdfIn PDF document text
    • http://alfatreyd-mebel.ru/archive/images/file/37361957142.pdfIn PDF document text
    • http://xn--j1aai7d.xn--p1ai/userfiles/file/ziganakizugoxizeludupaj.pdfIn PDF document text
    • https://www.almuhja.com/ckfinder/userfiles/files/49516410497.pdfIn PDF document text
    • https://mobilaide.com/upload/editor/file/zimife.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1613aae6675211---93335451324.pdfIn PDF document text
    • https://sunrise-photon.com/upfiles/editor/files/52823523183.pdfIn PDF document text
    • https://mollis.rs/files/50850501495.pdfIn PDF document text
    • https://www.dekleinewerf.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613ff032c748b---labegijerupiwerusig.pdfIn PDF document text
    • https://noticky.net/akce/fotky/file/mesemijaxowaleni.pdfIn PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/161423131191c5---pebipa.pdfIn PDF document text
    • https://tahitotfaluovodak.hu/ckfinder/userfiles/files/gadupukasogexigotunezu.pdfIn PDF document text
    • https://impeka.lt/components/com_mijoshop/opencart/image/data/files/gepelafewi.pdfIn PDF document text
    • https://egc.ecrom.work/syo/files/zazexadona.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_off0000bfc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBFC9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d7db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7DB 16716 bytes
SHA-256: c6b72e79364873686cad09ca26f83ee402b0396dbbad15eefb397a09ab02bb87
font_02_sfnt_off0001034d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1034D 10668 bytes
SHA-256: f02f8185ef437307cb4832a7c020877a18b75c20ac9a430a9d13799a725e4c8a