Malicious PDF — malware analysis report

Static analysis result for SHA-256 bcd07eab63a2e211…

MALICIOUS

PDF

70.8 KB Created: 2021-06-26 00:35:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7c94ccb8ae1a64783234174739816e47 SHA-1: 3395a319ef79a3d95b26ba4c59e074ce7f86a96e SHA-256: bcd07eab63a2e211707aa5c474dbf528cf24da38a749d41818007688d900009f
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of links pointing to other PDF files hosted on compromised WordPress sites. This behavior is indicative of a link farm, potentially used for SEO manipulation or to distribute further malicious content. While no scripts were directly extracted, the ML classifier strongly flagged this PDF as malicious, and the presence of numerous external links on compromised infrastructure supports a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

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 https://saftanton.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160b82594d95d6---25918748659.pdf
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/0b55f1dbc7072fd10b5132e04470eeb2/besazikitunosizenugar.pdf
    • https://yuktiedu.com/wp-content/plugins/super-forms/uploads/php/files/22596d8e0a5a428c51f789c2fb1f09c3/2249001597.pdf
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/7dd3666377415611c26aea51a4af9be0/6285385727.pdf
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160cd03fa4a328---53447285729.pdf
    • http://www.lauricedale.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160867b9eaedc7---63930318080.pdf
    • https://event-connections.net/wp-content/plugins/formcraft/file-upload/server/content/files/160961e883d152---zelosegifisadotitixu.pdf
    • http://abpaluso.com/upload/file/86700832073.pdf
    • http://chelseacarpet.com/ckfinder/userfiles/uploads/nukejikikijizov.pdf
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/160727b9dc7c36---4508433097.pdf
    • http://www.immiflex.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607feebb95f85---57986939667.pdf
    • http://www.advancedevents.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16070e73419d8a---70949475934.pdf
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160841609cec38---88570990306.pdf
    • https://www.sadcmedia.com/wp-content/plugins/super-forms/uploads/php/files/bn3kfu10hcn89f16s8elu8r288/dugedurabujebigosi.pdf
    • http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a56575cc303---nonalikowamomoviwi.pdf
    • http://learnazia.com/fck/imagesfile/gazibixagopedoxalavaruz.pdf
    • http://www.dj-csnl.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609fbfd511696---zuwidogiledilukijagi.pdf
    • https://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/16077032b2bcd2---47822099756.pdf
    • https://askisan.com/upload/ckfinder/files/dofoxogaxukop.pdf
    • https://www.themeshcowork.com/wp-content/plugins/super-forms/uploads/php/files/3c468e7be893cb62d1d9f16d317b0ec6/jagukinekawenasirum.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082797bef3fb---tizovuzepomi.pdf
    • https://www.qbuildsoftware.com/wp-content/plugins/super-forms/uploads/php/files/bd37e8f7001c0bff05023cdcb8550d0c/gilurajekeded.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f1bb4af368---dabilegajabubinunabox.pdf
    • http://happyland-nsk.net/ckfinder/userfiles/files/84339830680.pdf
    • http://www.loockuniformes.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/16072fdff6a70c---28946473862.pdf
    • https://jiptv.nl/wp-content/plugins/super-forms/uploads/php/files/8orlh3lfo6pnlntotu9aplav8a/71452299294.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=meters+to+yards+squared
    • 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_off0000b90c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB90C 16792 bytes
font_01_sfnt_off0000d11e.bin
bea77e4bf85ebe4860492231a983e9ad341d6d3d059b32509a0e6ab8f42d013b
pdf-font-stream PDF embedded font (sfnt) at offset 0xD11E 14992 bytes
font_02_sfnt_off0000f6c0.bin
0c77382ffe5382039fdbb96d6e8eab7215382caf33f0d6efc961b4b51d85ee97
pdf-font-stream PDF embedded font (sfnt) at offset 0xF6C0 10352 bytes