Malicious PDF — malware analysis report

Static analysis result for SHA-256 3886a25b14d0bb2e…

MALICIOUS

PDF

81.5 KB Created: 2021-07-05 21:13:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: a0fd7e45992062cf0836bf89d2af2566 SHA-1: dba8064caec822dc763f324b1e4a72c630763953 SHA-256: 3886a25b14d0bb2e3a33c3be34afea4cd0c835c5a83d5d21377fd0ab9791d6d7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URIs and link farm patterns, suggesting it's designed to redirect users to potentially harmful websites. The presence of PDF-specific heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' further supports this, indicating a tactic to obscure the true destination or leverage compromised infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://huntic.ru/uplcv?utm_term=how+to+underline+text+in+pdf PDF link annotation
    • https://boumqueur-edition.com/upload/fckeditor/file/82603648571.pdfIn PDF document text
    • https://flylights.pl/wp-content/plugins/super-forms/uploads/php/files/itoct93vh8b233befvdmlqij8j/sukofesumakegovepa.pdfIn PDF document text
    • http://www.nomorcantikjoss.com/file/nelitodabido.pdfIn PDF document text
    • http://a-kamen.com/userfiles/file/jowapakopuzego.pdfIn PDF document text
    • http://imcborivali.org/userfiles/file/tutopasa.pdfIn PDF document text
    • http://ibb-online.ru/f/file/xevefuwipesovalefeze.pdfIn PDF document text
    • http://kozszemle.hu/uploads/files/wativodaselidi.pdfIn PDF document text
    • http://fenotropil.ru/userfiles/file/wutinoporifuduxeb.pdfIn PDF document text
    • https://xn--i1aam8cb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/0b09593ad0ea979a03d6d04ec425297d/88707396304.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f8f4736ea3---89023080461.pdfIn PDF document text
    • http://www.alwaysflorida.com/wp-content/plugins/formcraft/file-upload/server/content/files/16070bd0f5392d---reninuwifu.pdfIn PDF document text
    • https://www.heainc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607851d24b276---gemoxireguzokisijavumoz.pdfIn PDF document text
    • http://findmealocalpainter.com/insurazon/admin/userfiles/file/27431583357.pdfIn PDF document text
    • http://hungthanhauto.com/luutru/files/rozulafuwasewatogu.pdfIn PDF document text
    • https://tenekedjieva.com/uploads/file/kenirifa.pdfIn PDF document text
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/98bef3d5fec34267e09c243de8d38342/73648109743.pdfIn PDF document text
    • http://meta-min.com/files/zifamexofutir.pdfIn PDF document text
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/160990b8fdd01e---50855056057.pdfIn PDF document text
    • 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_off0000dae0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAE0 10440 bytes
SHA-256: e400f95bb26d07db97fef11bdc50992aaa73c52290b27634fcc48c669406c8a6
font_01_sfnt_off0000f2a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2A0 17092 bytes
SHA-256: 935c3b11180271bd9010bfba735d75090b5ec076c4fa53c0149b72c2f280a78d
font_02_sfnt_off00011f87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F87 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1