Malicious PDF — malware analysis report

Static analysis result for SHA-256 f336851da1961553…

MALICIOUS

PDF

86.8 KB Created: 2021-06-30 22:41:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: a142ebba7b2ec70e415e1db8a07c6238 SHA-1: a7c0ede12aa759141ef16ee0e520880b88eb0433 SHA-256: f336851da1961553769f536fff43323c74326c1558b023744c38f9280758dd63
96 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to websites that appear to be compromised CMS uploads, specifically WordPress. The ML classifier strongly indicated maliciousness, and the heuristic firings suggest this PDF is part of a link farm designed to direct users to potentially malicious content or for SEO manipulation. No scripts were extracted, limiting the analysis of direct execution vectors.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 5

  • 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 http://karinameal.com/imgdish/files/bajijofakalazajepodelowu.pdf In PDF document text
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/160753e58d9ff8---11566243603.pdfIn PDF document text
    • http://szpital-sulecin.pl/images/fckfiles/file/87736263852.pdfIn PDF document text
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608ecb3b6747f---38662438371.pdfIn PDF document text
    • https://propertiproperty.com/Uploads/userfiles/files/vogod.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/3dv0ka0fi4hte131f1fd1ep6u9/malozije.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a72ccc8cec8---nipase.pdfIn PDF document text
    • https://247hvac.ca/fabulous1/uploads/files/fubisowos.pdfIn PDF document text
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a26cdd24d24---42003248423.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16080b4fe9f373---koxonesesu.pdfIn PDF document text
    • http://dui-antidote.net/images/userfiles/file/vulelabowulor.pdfIn PDF document text
    • https://lostsoulsmemorialnj.org/wp-content/plugins/super-forms/uploads/php/files/d37617a1c8281cf9b810471e88b5d36b/51334140349.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ebd2977bdb---wexupovamewuwofekojoz.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1608103cf17164---noxapovowelumubobural.pdfIn PDF document text
    • http://matstravel.ru/userfiles/file/kuwavutowogemolerito.pdfIn PDF document text
    • http://cukiernia-waltar.pl/qcms/userfiles/file/sosuzufeji.pdfIn PDF document text
    • https://razdolle.by/wp-content/plugins/super-forms/uploads/php/files/82jn7605o4drmicpesf459cqk5/wuguxesefoko.pdfIn PDF document text
    • http://brkvinc.com/userfiles/file/xopizitesiduxinilukev.pdfIn PDF document text
    • http://palyavalaszto.hu/teszt/upload/file/80973766996.pdfIn PDF document text
    • http://nguyenthaotech.com/upload/files/83684927270.pdfIn PDF document text
    • https://dmvassociates.com/wp-content/plugins/super-forms/uploads/php/files/1e7f8a880372fc998c561f3e4e57fe01/mitarigibituzud.pdfIn PDF document text
    • http://fxmeat.com/upload/file/9b501eff433585cc4d556ef8c0db85bb.pdfIn PDF document text
    • https://tenshinorchids.com/FCKeditor_upload/file/felexuguzabepowel.pdfIn PDF document text
    • http://daming-school.com/userfiles/file/sejam.pdfIn PDF document text
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607f6a6a13a91---88135134988.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=all+good+things+come+to+those+whoPDF 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_off0000f232.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF232 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010a49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A49 10624 bytes
SHA-256: 50b77dd3fe34dc75c77ad88c7c451e29cb0c0f83e88490ae64f0fefd813666d8
font_02_sfnt_off0001223c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1223C 16840 bytes
SHA-256: b0f9ac77583b9a5d1b58a2419e29cb94e3dae9abb16ab961a2f66bffb7229777