Malicious PDF — malware analysis report

Static analysis result for SHA-256 d816d831a09af0b7…

MALICIOUS

PDF

69.3 KB Created: 2021-09-29 00:02:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 750182422d4dc6e50f136a5b21ea9e0f SHA-1: 5eb25e0421e7da19f2e45827aac3a3acb4e880ce SHA-256: d816d831a09af0b7c40690c0547a907bbf800f1ae7df92842e7d6b305cad3c5c
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm with numerous URLs, many hosted on compromised CMS platforms or disposable domains, suggesting an attempt to distribute malicious content or phish users. The ML classifier strongly indicated maliciousness. Although no scripts were directly extracted, the presence of embedded URLs and the heuristic findings point towards a malicious document designed for initial access via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://portalkucharski.pl/app/webroot/media/files/valoxaxagufeko.pdf In PDF document text
    • http://naturestuff.nl/siteimages/file/71482920244.pdfIn PDF document text
    • http://janaturismointegrato.com/uploads/file/fiwimobewumenu.pdfIn PDF document text
    • http://www.radanhorse.com/resource/files/gefadusugewaxuxikobajoba.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/16152e4dc67243---89051676353.pdfIn PDF document text
    • https://at-studio.tw/app/webroot/userfiles/files/20210910_001935.pdfIn PDF document text
    • http://onlytech-tunisie.com/userfiles/file/segazugunolavudusokinema.pdfIn PDF document text
    • https://stmarys-perthamboy.com/upload/File/pojivasopozibat.pdfIn PDF document text
    • http://zgic.ru/!upload/files/569293862.pdfIn PDF document text
    • https://vegas-shop.net/uploads/files/30360601942.pdfIn PDF document text
    • http://congtyvima.com/images/Download/xozaxojifimu.pdfIn PDF document text
    • http://gzky.cn/dubeite/ckfinder/userfiles/files/20210919_092519.pdfIn PDF document text
    • https://estidevelopers.com/wp-content/plugins/super-forms/uploads/php/files/cf7ac544121d9aa66ddc484f78c65802/bikiraxe.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/161434d093abdd---pamedawelumajusoduxome.pdfIn PDF document text
    • http://domadoma.cz/userfiles/file/54816052478.pdfIn PDF document text
    • https://festivaldelmaridaje.com/sgi_userfiles/userfiles/files/13817006986.pdfIn PDF document text
    • http://stickers-moins-cher.com/userfiles/stickers-moins-cher.com/file/15858458233.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/q5jtkt6tjhhklhknhr23iptk13/gusopabunikenof.pdfIn PDF document text
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/03191cd2de2b76e2f8876ab8b390f1c2/64213553084.pdfIn PDF document text
    • https://ver9.sonikgps.com/ckfinder/userfiles/files/vovedulupesizovil.pdfIn PDF document text
    • https://daaeportrett.no/upload/file/pusapomefopodavofigugi.pdfIn PDF document text
    • http://thenikharvconsultancy.com/userfiles/file/mixujijelivu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=pes+2017+play+storePDF 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_off0000b12e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB12E 10508 bytes
SHA-256: 2ead48e7b979fde5334ff63d6408559ab3841dc6b1781ca27eda0bfbd7eaa090
font_01_sfnt_off0000c97d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC97D 15128 bytes
SHA-256: 645c669f6c8ca38d7bdc909da8cdf89810b69bbb6295e1de56283bec9f998b57
font_02_sfnt_off0000efb5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFB5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1