Malicious PDF — malware analysis report

Static analysis result for SHA-256 e99ca098744688ca…

MALICIOUS

PDF

71.1 KB Created: 2021-09-24 01:45:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 12a261393a72597e0e66e685476088cd SHA-1: 59360c7b2d12d75027057998a29cdfc8ccd09432 SHA-256: e99ca098744688ca2393dd41be6cb4489493738b3f4244a112e8b970df80ca9d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs that form a link farm, with many pointing to compromised CMS uploads or disposable hosting, indicating an attempt to distribute malicious content or conduct phishing. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, lacking clear user-facing text but containing numerous links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 http://konsultacjenaukowe.eu/Upload/file/magakoko.pdf In PDF document text
    • https://themodernla.com/wp-content/plugins/super-forms/uploads/php/files/8369831db9569d87aa868b2be2b94ef5/27650315113.pdfIn PDF document text
    • https://cleartunemonitors.com/ckfinder/userfiles/files/66647671572.pdfIn PDF document text
    • http://gomsuhoangminh.com/app/webroot/uploads/files/1834129704.pdfIn PDF document text
    • https://lenaoyunlar.com/calisma2/files/uploads/rutedonixixowasogebaxanon.pdfIn PDF document text
    • https://atputasbazes.lv/images/userfiles/files/76357936895.pdfIn PDF document text
    • https://mediabandit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614c748397f54---63215045690.pdfIn PDF document text
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/b221b7d9ac4cc065171462b85751669f/97491906001.pdfIn PDF document text
    • http://hvpeds.com/upload/contents/file/91235175045.pdfIn PDF document text
    • http://xn--90aoa5aj.xn--p1ai/ckfinder/userfiles/files/koxudofofubuwikuf.pdfIn PDF document text
    • https://beaszemin.com/files/sokafiniwezewi.pdfIn PDF document text
    • http://tscyw.net/userfiles/file/20210903014528_f5m71y.pdfIn PDF document text
    • https://underworldgear.com/upload/users/files/gufitadalefimu.pdfIn PDF document text
    • https://shiksha24.com/userfiles/files/zelemowafanisosiruj.pdfIn PDF document text
    • http://simkoongschool.com/uploads/editer/files/95832957874.pdfIn PDF document text
    • http://wieswioska.pl/userfiles/file/57807094364.pdfIn PDF document text
    • http://roseeskin.com/userfiles/file/20210907100848.pdfIn PDF document text
    • http://www.firengo.com/userfiles/files/12513120734.pdfIn PDF document text
    • https://ferado.vn/userfiles/file/jiruw.pdfIn PDF document text
    • https://ceccardolj.ro/userfiles/file/nezarozejenurewupenoraso.pdfIn PDF document text
    • http://opersan.com/file/10421999728.pdfIn PDF document text
    • http://xhzhengli.com/upload/68892050685.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=gifted+movie+torrent+downloadPDF 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_off0000b460.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB460 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cc72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC72 16564 bytes
SHA-256: 1aeec5d1a5b2f21a3d07761424e99b18c36b9e57af3f996912f3cc61fa5ec339
font_02_sfnt_off0000f73c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF73C 10540 bytes
SHA-256: 9cba726aa6db145c7d393a5f5f518cc9748d9564c6cfb35f37e20388953ac2a9