Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef920bbb0b31199f…

MALICIOUS

PDF

84.0 KB Created: 2021-09-05 12:23:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 5534193de6a2226b0c1a5d934405071c SHA-1: b7fdf4d3e8be3883feedf72c329a7d05b2f9cb15 SHA-256: ef920bbb0b31199f272b4e927dbcb6902a8918532d345b1139edd23cffd22eda
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised CMS uploads or disposable hosting, indicating a link farm designed to redirect users to malicious sites. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics strongly supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://ksnjl.com/userfiles/files/xawujudeloxibimijorak.pdf In PDF document text
    • http://xn----8sbpvg0afdbe.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/982650h99rf51emt7nflb61li0/puwoliginaxidotod.pdfIn PDF document text
    • https://haps.company/wp-content/plugins/super-forms/uploads/php/files/u786ul50luvau12ood56c8lvj4/lupuliju.pdfIn PDF document text
    • http://cisseo.net/userfiles/files/papuw.pdfIn PDF document text
    • https://distriparkbotlek.nl/userfiles/files/mojozamiloz.pdfIn PDF document text
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/5bd047d9b71c3c8505902d70bbf89715/74249848984.pdfIn PDF document text
    • http://www.toeterloeh44.de/files/zagife.pdfIn PDF document text
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/41eb33b0132c6ccca48f0b70f75a7d44/20647960944.pdfIn PDF document text
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/2g6ojbek5mhua1biohdlrv5lh5/2940449184.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/0792abdd70ddf48b622ab30150a8781e/86526321540.pdfIn PDF document text
    • https://readandenjoy.ae/userfiles/files/bebewowerutadowebejawe.pdfIn PDF document text
    • http://chuaphucluong.com/uploads/image/files/wafukulenegoxeruxidisutas.pdfIn PDF document text
    • http://xn--80aaeiengkwpz6p.xn--p1ai/pub/file/feneri.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/1610cb0ec311bf---10684474210.pdfIn PDF document text
    • http://daindnc.com/fckeditor/userfiles/file/fajapek.pdfIn PDF document text
    • https://stradatextiles.com/upload/ckfinder/files/jezafuwak.pdfIn PDF document text
    • https://globalazeri.az/wp-content/plugins/super-forms/uploads/php/files/47h6emkh0hi67d08bbf2i87c57/fuwuxalugorotojolesogi.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/16109cd61f2db3---48209347712.pdfIn PDF document text
    • https://seerupit.dk/assens/file/91386323320.pdfIn PDF document text
    • https://spitalmoldovanoua.ro/ckfinder/userfiles/files/poxulixowivalas.pdfIn PDF document text
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/gg4roaj5r99abr51hgqa214lc8/85938217860.pdfIn PDF document text
    • http://benthanhsgfarm.com/images/uploads/files/79596604805.pdfIn PDF document text
    • https://area34.info/wp-content/plugins/super-forms/uploads/php/files/vq1u6t1tvg7nnujuqtscsiamt5/wifaviduzotekoxuwakeruga.pdfIn PDF document text
    • http://xn--80aaaaaikdebj9ccf1ayja1b5a3q.xn--p1ai/ckfinder/userfiles/files/63458380481.pdfIn PDF document text
    • http://madveras.com/ckfinder/userfiles/files/84247804787.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=geopolitics+and+world+economic+system+pdfPDF 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_off0000df8a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF8A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f7a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7A1 11020 bytes
SHA-256: 8d722afdb18a19dd3695a03c031404d3993c708f22d059b9573ae93e7412613c
font_02_sfnt_off00011159.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11159 18632 bytes
SHA-256: 78ea6debb0d6b65d320e69ac7d2d9070ada91928eedec34e76b9e32f2837c32e