Malicious PDF — malware analysis report

Static analysis result for SHA-256 9818934275318f63…

MALICIOUS

PDF

86.5 KB Created: 2021-08-08 23:55:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: e2cdf07c2e610ca73ea1705608edd37e SHA-1: 8d90a3bbbe937193d92dcc201ec3b06195dc0915 SHA-256: 9818934275318f6344be6e02b3dac69057709832a0b9b6daabae7e49222d67ab
96 Risk Score

Malware Insights

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

The PDF contains a large number of links pointing to files hosted on compromised CMS upload directories, indicating a link farm or distribution mechanism. The ML classifier strongly flagged this PDF as malicious, and the heuristics indicate it's part of a link farm on disposable hosting. No scripts were extracted, but the overall structure suggests it's designed to lead users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608548aae0cd4---89583755783.pdf In PDF document text
    • https://feniks9.ru/ckfinder/userfiles/files/pukatetonidalelopodofosa.pdfIn PDF document text
    • http://salt17.com/userfiles/files/38883380324.pdfIn PDF document text
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b1a1801397f---ferolulukinijinexekeruj.pdfIn PDF document text
    • http://frangarcia.eu/upload/file/bosebokilijuver.pdfIn PDF document text
    • http://wittlich-luexem.de/userfiles/file/bazududunetuzozup.pdfIn PDF document text
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/329895cd12554d65afd40d9b569cd814/fotawebokirovono.pdfIn PDF document text
    • https://www.properties-thassos.com/wp-content/plugins/super-forms/uploads/php/files/m55keiufuil4k1enj0td5cq9ka/muruke.pdfIn PDF document text
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f462f11250d---7486060042.pdfIn PDF document text
    • http://herbwaterthailand.com/userfiles/files/95171280598.pdfIn PDF document text
    • http://gesundezellen.de/neu/userfiles/file/zutorazerozemupar.pdfIn PDF document text
    • http://www.circoloaletrium.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a44b6424f60---4954670320.pdfIn PDF document text
    • http://bamt.be/wp-content/plugins/formcraft/file-upload/server/content/files/160ab8e3daa2e2---powogewinozenepagosagad.pdfIn PDF document text
    • https://finatwork.com/userfiles/file/86290043206.pdfIn PDF document text
    • http://araonline.hu/uploads/file/tipagudasavosamura.pdfIn PDF document text
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a3fdb323d75---faxaweravofemuzetuzolav.pdfIn PDF document text
    • http://rafaelstore.ru/upload/files/59283570766.pdfIn PDF document text
    • http://maynenkhipuma.vn/quangbasanpham/app/webroot/upload/image/files/27692981683.pdfIn PDF document text
    • http://qiuyutv.com/userfiles/files/20210531061348.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2bfc040cc9---gozoseziwerodoniseki.pdfIn PDF document text
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081263c490de---67880990092.pdfIn PDF document text
    • http://www.morrisjones.co.uk/EditorImages/file/36851247657.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=present+perfect+negative+examplesPDF 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_off0000ee08.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE08 16720 bytes
SHA-256: 9a6e637f06136d7e0b5e4c51f884933c3b5e5c1c5391ae2e1cffd4e815bbcb45
font_01_sfnt_off00011962.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11962 10872 bytes
SHA-256: 4a8c6420b85903d329ba190834a8011dcc96e3b736ea887211e5257df12b5b6c
font_02_sfnt_off00013294.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13294 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1