Malicious PDF — malware analysis report

Static analysis result for SHA-256 81764820efca4519…

MALICIOUS

PDF

86.5 KB Created: 2021-09-23 22:11:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1aab830ce0f9b19ff3e7a99144142dad SHA-1: 55496c550d5a2282c267bc871662143dbc3d0b3d SHA-256: 81764820efca4519c8e64f172b11d9ac51dcd1f967135d37807ccb7209f85b09
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics, including a critical ClamAV detection for 'Pdf.Phishing.Trojan'. It contains numerous embedded URLs pointing to compromised WordPress sites and disposable hosting, suggesting a link farm designed to redirect users. The ML classifier also strongly indicated maliciousness. While no scripts were explicitly extracted, the presence of external links and the overall detection profile point towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://oniceh.ru/uplcv?utm_term=vlc+vs+mx+player+android
    • https://bimstudioinc.com/media/files/26913262372.pdf
    • https://mikepromedia.com/wp-content/plugins/super-forms/uploads/php/files/c343026fde08bdb9ce7b3a667ed79ba7/93572900289.pdf
    • http://inkjetartandimage.com/Uploads/file/giluvomo.pdf
    • http://jowinbio.com/upload/files/202109230055548284.pdf
    • https://evpersoneli.net/ev-personeli/file/subunopepafakugizunuguta.pdf
    • https://bem-sa.com/img/file/rovajozuvifuguni.pdf
    • https://protradingindia.net/userfiles/file/52064425423.pdf
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/230b41ad8755f4ee4bea11bb6fe085a1/12549287036.pdf
    • http://gsoam.ge/wp-content/plugins/formcraft/file-upload/server/content/files/161334ad7becde---fuwogibizipe.pdf
    • http://veronikavilla.hu/userfiles/file/31043401620.pdf
    • http://purel-biopharm.com/upload/files/98167589471.pdf
    • http://0975811252cool.linker.tw/files/wufedilu.pdf
    • https://next-engineering.com/userfiles/files/29484944448.pdf
    • http://liqaa-lb.com/files/userfiles/files/bapexizu.pdf
    • http://accessiblevehicleservices.com/userfiles/file/butugasixonuru.pdf
    • http://smartwealthhk.com/userfiles/mavejo.pdf
    • https://thefertilizerproductionline.com/d/files/18000257214.pdf
    • http://lpc2529.com/piceditor/file/rulolonirajazoxetoba.pdf
    • https://colakcivi.com/userfiles/file/vekejifetilamerolozis.pdf
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/ef5628c93ca6c789f4ad36604c71d688/mebevalesofuda.pdf
    • https://camelcarpet.org/d/files/80936410330.pdf
    • https://delta-relay.be/userfiles/file/2297689259.pdf
    • https://hsiaoying.com/userfiles/file/wironeve.pdf
    • http://studioarchperissinotto.eu/userfiles/files/suvoriritogazuwiw.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ec22.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC22 16792 bytes
font_01_sfnt_off00010439.bin
37320cf785c356c9c9ccd60ec9592cebe1490349605df8e381826cea9cc70418
pdf-font-stream PDF embedded font (sfnt) at offset 0x10439 10828 bytes
font_02_sfnt_off00011d2f.bin
f9e397f16d84a625008422a9a1cd1aea88eb21d7df54f71ced6b1d800aea5328
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D2F 18432 bytes