Malicious PDF — malware analysis report

Static analysis result for SHA-256 aaef23d4afce6951…

MALICIOUS

PDF

89.6 KB Created: 2021-08-14 12:09:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: fe9db892128f8a5e6fb9a6c389668d9c SHA-1: c1a1f5f0f6c2f258bd82068ab23dbc56de32f2cc SHA-256: aaef23d4afce69512c39dc15d27a560a6c214a210e016a371031bc46d2f5a722
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF detected as malicious by ClamAV and an ML classifier. It contains numerous embedded URLs, many pointing to compromised WordPress sites, suggesting a link farm or phishing lure. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics indicates a deliberate attempt to leverage compromised infrastructure for distribution. No scripts were extracted, but the overall structure points to a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://www.hdcorp.com.br/wp-content/plugins/super-forms/uploads/php/files/66h2fau12tt3ihjb94ibjglujj/xufuzujolufi.pdf In PDF document text
    • http://www.sempresaude.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609f22e158af0---notokavamanubupizijudagat.pdfIn PDF document text
    • http://barexkft.hu/userfiles/file/64594744448.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160823c9728b23---zasireripodulasulubifabuf.pdfIn PDF document text
    • http://thm-holding.ru/wp-content/plugins/super-forms/uploads/php/files/d001bceaf589c97e308e7b107cebb644/46246031062.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c03f6d2aac8---xeduzagere.pdfIn PDF document text
    • http://heizler.hu/files/file/84049055114.pdfIn PDF document text
    • https://www.cibaospalaser.com/wp-content/plugins/super-forms/uploads/php/files/3opgme0cnpha7q4uil7munrupn/newavowezagituseki.pdfIn PDF document text
    • https://svetplus.com/userfiles/files/wotitanufagugole.pdfIn PDF document text
    • http://maynenkhiinverter.com/media/ftp/file/3252943292.pdfIn PDF document text
    • http://zonazero.es/userfiles/file/290955059.pdfIn PDF document text
    • http://nissanotogovap.com/uploads/images/files/pusewumef.pdfIn PDF document text
    • http://www.realisthotel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3a9b9ce415---mijexozagavuxikamakena.pdfIn PDF document text
    • http://soundspace.eu/Upload/file/13266534749.pdfIn PDF document text
    • http://anhuifan.com/upload_fck/file/2021-5-2/20210502011953236708.pdfIn PDF document text
    • http://mdknoodles.co/uploads/files/kujakusugubulugowaxolo.pdfIn PDF document text
    • https://bepxuyenviet.com/upload/files/83195917240.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/160f2392d0f164---1603174163.pdfIn PDF document text
    • http://uyaviation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090f6aa8b2d4---getinaw.pdfIn PDF document text
    • https://archcosmeticstudio.com.au/wp-content/plugins/super-forms/uploads/php/files/1ea8e6bfded5dab6be589e2f8b6626b6/gojidawa.pdfIn PDF document text
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/160738e597656a---95311379765.pdfIn PDF document text
    • https://www.unicodesystems.com/wp-content/plugins/super-forms/uploads/php/files/86pamkd08bo65jbo3fjb6cb6d1/83793513852.pdfIn PDF document text
    • http://connect-event.fr/ckfinder/userfiles/files/zetaladinopega.pdfIn PDF document text
    • http://propellerclubsandiego.org/uploads/files/81141335184.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=libro+coaching+pnl+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_off0000fa4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA4B 10600 bytes
SHA-256: 8950d05bdf8e0b15fcdf4d4fe9f2267ea20ecf5589620c9b6c1031776c7a0329
font_01_sfnt_off000111e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111E4 17516 bytes
SHA-256: 178a0b6b48f1552df22b1fe03455ff287d9ea55976554f362679dc125f3ca619
font_02_sfnt_off00013f99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13F99 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1