Malicious PDF — malware analysis report

Static analysis result for SHA-256 cdcf8c18834104b2…

MALICIOUS

PDF

94.4 KB Created: 2021-07-13 04:28:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 4484acfc6e418ef9cfefd8aca9c53e18 SHA-1: 6b4a4ea9776d891d6bf95b74412d6c51fb302bc5 SHA-256: cdcf8c18834104b2a71b8f3a3b69c48a7ab756165c840d2e06a74996a5ecf15a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of external links, many of which point to compromised WordPress upload directories. The ML classifier and ClamAV both flagged this PDF as malicious, indicating a phishing or trojan distribution attempt. The primary attack pattern involves directing users to potentially malicious content hosted on compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9924

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://simondaulte.com/ckfinder/userfiles/files/valurebo.pdf In PDF document text
    • https://www.rogierstoel.nl/wp-content/plugins/super-forms/uploads/php/files/70vbcsigedlbuik38hcl3u4257/54670688086.pdfIn PDF document text
    • http://helder-effect.nl/userfiles/file/67794607898.pdfIn PDF document text
    • https://unique.global/wp-content/plugins/super-forms/uploads/php/files/55d0eb22b19e0f9c10dfdc5f49e776ed/fujinubewipuliko.pdfIn PDF document text
    • http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16088eaf03aadc---6619632643.pdfIn PDF document text
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160746601b2e41---gemusuguxatugibuneg.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/jifukapisibodo.pdfIn PDF document text
    • https://sandzak.best/wp-content/plugins/super-forms/uploads/php/files/e03be31452fbb65f1c82bb91399dd88f/68723183362.pdfIn PDF document text
    • http://lamekatus.ee/uploads/ckeditor/files/kaposeziwitusabokasawep.pdfIn PDF document text
    • http://uk-finansist.ru/userfiles/file/34589375776.pdfIn PDF document text
    • http://airconbank.com/upload/fckeditor/file/39897402600.pdfIn PDF document text
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/16075cff17a5d2---nijunifujolozomorul.pdfIn PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/0f6e49c8f9f3b580388b3ffaab150ccf/28445898782.pdfIn PDF document text
    • http://vyveva.eu/UserFiles/File/91766940599.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607378e6ef9c2---fefinedow.pdfIn PDF document text
    • https://skazkavdom.com/wp-content/plugins/super-forms/uploads/php/files/12a87bb39d10ecd0bbcdaa021855f709/6965126431.pdfIn PDF document text
    • http://intestinalfortitude.org/clients/0/0c/0cf504f131cb0201443a7bd449519f4a/File/rikojofekewepobijipev.pdfIn PDF document text
    • http://training-solutions.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606fd5df44446---26826175959.pdfIn PDF document text
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085ff7615d37---6911542953.pdfIn PDF document text
    • https://www.frankreich-ferien.ch/wp-content/plugins/formcraft/file-upload/server/content/files/1607b70b11ea0e---gejij.pdfIn PDF document text
    • https://baconbites.com/wp-content/plugins/super-forms/uploads/php/files/9ppa397atuahk5hd8s67huuk03/tikovobivokalitupi.pdfIn PDF document text
    • http://albatrossmrn.com/konadnew/userfiles/file/wiforexat.pdfIn PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/ui6ttb5gsjdppsd16tkobdsge3/lupuranivugobuja.pdfIn PDF document text
    • https://www.hintonassociates.com/wp-content/plugins/super-forms/uploads/php/files/8b03a395056a71e863646cf961f8e125/26353787992.pdfIn PDF document text
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/4ad3a903e501ab1943060017e34e82b0/rijanufeduzonam.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=7th+class+maths+questions+and+answersPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001056a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1056A 1780 bytes
SHA-256: ee6d8c25003eb2de61ee1fda640ec7b8e4605923364b71ee832b966c85f0f81c
font_01_sfnt_off00010dc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DC9 17140 bytes
SHA-256: 34a64b5ee669b2e512b56836548621b7a1fed3c65432deb4effb4f10a3e61145
font_02_sfnt_off00013ac1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13AC1 10920 bytes
SHA-256: 05f8305238436ecde0ad83bc2a3f8bee86f21bb3829a3bc453f73f14d02f6280
font_03_sfnt_off000153c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x153C0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1