Malicious PDF — malware analysis report

Static analysis result for SHA-256 43259ac4c56c130a…

MALICIOUS

PDF

90.0 KB Created: 2021-07-07 20:13:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: f9d1fd0055c1d196ef29796f7524af62 SHA-1: e0aae7f043ef5b72199e22848bc863ddbbd675fc SHA-256: 43259ac4c56c130a12647f3a9c9e52472b830ce4319f8a4aecb0b50bee22aab6
156 Risk Score

Malware Insights

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

The sample is a PDF document that utilizes a link farm hosted on compromised WordPress sites. Multiple heuristics indicate that these links point to other PDF files, suggesting a multi-stage redirection or download process. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, and the document body was unreadable binary data.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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.finestkindcharter.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092c995dd7a1---98533507749.pdf
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081cd8ebc085---tomubenubojaru.pdf
    • https://himalayanwanderer.com/himalayan/userfiles/files/11949880215.pdf
    • http://tdbakademi.org/userfiles/files/pameramapuwokeko.pdf
    • http://adoriantarla.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160dc0a2649bce---widemanirofafas.pdf
    • https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16083ae28ca97a---10711055050.pdf
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160c9fe025d0ae---rafekabol.pdf
    • https://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/5c4927064239f35de981cbc03eb546ef/82570084355.pdf
    • http://kutscher-customs.de/gfx/userfiles/files/fodizutaposiboreve.pdf
    • http://audiencefertilization.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/xofafimubiwu.pdf
    • http://doubles301.jp/files/ckeditor/files/damimadosemol.pdf
    • https://tehnol.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606ce0426aebc---fegemunivig.pdf
    • http://www.unidacardoso.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607092ede0de0---87885368518.pdf
    • http://ozanatalan.com/iboard/includes/userfiles/files/mizaxibiro.pdf
    • http://sukhabalka.com/files/file/59182787094.pdf
    • http://kassa.pl/userfiles/file/padakenejomorupozat.pdf
    • https://csom.cz/wp-content/plugins/super-forms/uploads/php/files/d3572398a2d8da1f88b07316e9244e69/ninelaliderotifogugot.pdf
    • https://www.indoorclub-informa.com/boletines/img/file/moduvugesiju.pdf
    • https://gservicepz.com/wp-content/plugins/super-forms/uploads/php/files/89f881699f2d2239f5d9a99148d02713/mizugi.pdf
    • http://acmemask.com/upfiles/editor/files/pobaxuzuvidane.pdf
    • http://4seasonstours.in/userfiles/file/gefefufuxuda.pdf
    • https://dungcuruamui.com/wp-content/plugins/super-forms/uploads/php/files/kajmoqevp6li1ifsaa0pe87g3f/ginulep.pdf
    • https://westcoastmovers.ca/wp-content/plugins/super-forms/uploads/php/files/2tbqu1v8tq6uve21eul68u28fs/94802597237.pdf
    • https://sellerflows.com/wp-content/plugins/super-forms/uploads/php/files/16b6cfada930942f4e8e8801e156237d/jolozebojebobemenatoli.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=mary+todd+lincoln+age+at+death
    • 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_off0000fd11.bin
dc86bf7d5178e595f6809f0aae6cef751665a86fc3a74a9f60ba69ea6a12d6f0
pdf-font-stream PDF embedded font (sfnt) at offset 0xFD11 17140 bytes
font_01_sfnt_off00012971.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12971 16792 bytes
font_02_sfnt_off00014188.bin
5ebcdce34784e1d218922a5ba010956a9c789d3b08015808cfa86b577fd6749d
pdf-font-stream PDF embedded font (sfnt) at offset 0x14188 10588 bytes