Malicious PDF — malware analysis report

Static analysis result for SHA-256 4306c8ad29920217…

MALICIOUS

PDF

84.8 KB Created: 2021-09-18 09:05:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 3ec5f354312e0a309a95629f91914ab2 SHA-1: b4925e4894884e057455e380dd13479980ee2a47 SHA-256: 4306c8ad299202173fd12322b1fa5b6c4990231b5e525e3b7de68e3869d2b660
126 Risk Score

Malware Insights

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

The sample was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It contains numerous embedded URLs, many pointing to PDF files hosted on various domains, suggesting a link farm or SEO abuse tactic. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly indicates this malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 https://rebates.forex/wp-content/plugins/super-forms/uploads/php/files/vhjr47hflftkd5asqmg9rlek50/6423838626.pdf In PDF document text
    • https://jin-ji.com/upload/files/98202665180.pdfIn PDF document text
    • http://mawaevents.com/uploads/file/jawesarik.pdfIn PDF document text
    • http://mmsmarin.com/imgimage/file/29529382097.pdfIn PDF document text
    • https://www.ftha.org/admin/ckfinder/userfiles/files/pudab.pdfIn PDF document text
    • http://tamker.hu/userfiles/file/miwubowamanojonoduxivimux.pdfIn PDF document text
    • https://bocrangsuthammy.vn/upload/files/wisoserimiwalenemikaxoxaj.pdfIn PDF document text
    • http://thaicockstar.com/ckfinder/userfiles/files/kejalabobilesegigu.pdfIn PDF document text
    • https://ssmahavidyalaya.org/lion/uploadedfiles/fck/files/file/tobonuxogiluwifagov.pdfIn PDF document text
    • https://anzhero-sudzhensk.verlauf-ekb.ru/admin/ckfinder/userfiles/files/tegosob.pdfIn PDF document text
    • https://www.luxboss.com/ckfinder/userfiles/files/95614666726.pdfIn PDF document text
    • https://luxm.pl/userfiles/file/77665388604.pdfIn PDF document text
    • http://minhanh.com/files/newirarejerogiwoj.pdfIn PDF document text
    • http://studiotecnicodama.it/userfiles/files/suxonesivatek.pdfIn PDF document text
    • http://actionelectric.pt/www/wp-content/plugins/formcraft/file-upload/server/content/files/1612ff4ca649a5---fonijabaxoso.pdfIn PDF document text
    • https://dispomydeal.com/wp-content/plugins/super-forms/uploads/php/files/371264d10afea1947cbb4c8f06d704ff/koronup.pdfIn PDF document text
    • http://bluebirdcanada.com/FileData/ckfinder/files/20210918_1A4EA065EE331BC3.pdfIn PDF document text
    • http://snieznik.pl/userfiles/file/94198997867.pdfIn PDF document text
    • http://aqbnb.com/uploadfile/file/jibozoruvuk.pdfIn PDF document text
    • http://aftp.bg/userfiles/file/xakesebuzerube.pdfIn PDF document text
    • http://xn--12cfu9bc1efac9a9azfdsb7b9d1f0j.net/ckfinder/userfiles/files/44049317234.pdfIn PDF document text
    • http://xn----8sbfeahwarn6ac1adp3fb2p.xn--p1ai/userfiles/file/28744263478.pdfIn PDF document text
    • http://jagatjyotischool.org/jagatjyotischool/userfiles/file/63021862969.pdfIn PDF document text
    • https://zlataraburmevuckovic.com/files/42113123085.pdfIn PDF document text
    • http://unicaconsultoriarh.com/images/files/navuguse.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=guitar+tab+app+androidPDF 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_off0000e9ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9EA 17168 bytes
SHA-256: 08e09fd83c1d3ed3d2949d9fdab3c3d382b2e7215772e361b1c00b6848d556e9
font_01_sfnt_off00011669.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11669 10316 bytes
SHA-256: 0eaa96db363a2c825b94fe4a7256aa65b6852010c7549baa494e0283acd23f35
font_02_sfnt_off00012d85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D85 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1