Malicious PDF — malware analysis report

Static analysis result for SHA-256 d6aa86d734a18c08…

MALICIOUS

PDF

73.7 KB Created: 2021-09-16 01:30:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 1fceff9041be2cf1af3d42cb66b645fb SHA-1: 32b8f9254aeecab22d28a9c7a96c4850b4b863ca SHA-256: d6aa86d734a18c08eab6ec6c08630b310092e894397c5f0700e484a764dc5a9e
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which are hosted on disposable domains or compromised CMS uploads, indicating a link farm or redirection scheme. The ML classifier strongly flagged this PDF as malicious. The embedded JavaScript likely facilitates the redirection or further malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 6

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://rumusjitu.com/contents/files/vobajabetevubafopugedabiw.pdf In PDF document text
    • https://georeno.ca/userfiles/files/beluvoninodotu.pdfIn PDF document text
    • http://crabandclaw.com/uploads/files/lasupo.pdfIn PDF document text
    • https://comodee.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ae50fb36d7---bavililenuku.pdfIn PDF document text
    • http://profstil.az/userfiles/file/83407113564.pdfIn PDF document text
    • http://neoneophytou.com/ckfinder/userfiles/files/34549397493.pdfIn PDF document text
    • http://www.thegrcinstitute.org/app/webroot/js/ckfinder/userfiles/files/48126127878.pdfIn PDF document text
    • http://luligang.com/ckfinder/userfiles/files/rixifamaxomes.pdfIn PDF document text
    • https://10glazsikeyrosa.ru/file/vazeji.pdfIn PDF document text
    • http://hanasushimenifee.com/uploads/files/fisanuwojonit.pdfIn PDF document text
    • https://www.medicalart.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1612fcc382e42c---gitosumebijijajogipobenim.pdfIn PDF document text
    • https://rmissio.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613ff7c21e606---93106231913.pdfIn PDF document text
    • http://konferencii.org/js/ckfinder/userfiles/files/67156006459.pdfIn PDF document text
    • http://autolubitel-irk.ru/userfiles/file/zobeze.pdfIn PDF document text
    • https://candica.pl/ckfinder/userfiles/files/vefasow.pdfIn PDF document text
    • https://mackbeks.com/files/file/semasobetizanorupagojetej.pdfIn PDF document text
    • http://otestmanager.com/club/data/userfiles/file/20210908071319.pdfIn PDF document text
    • http://cjpharmtech.com/upload/files/nuvuzok.pdfIn PDF document text
    • https://zemiigori.com/uploads/file/80560312615.pdfIn PDF document text
    • http://bluelakehomestay.com/uploads/image/files/25276915053.pdfIn PDF document text
    • https://suacuachuyennghiep.com/uploads/files/kuvosimubulo.pdfIn PDF document text
    • http://reicar.dk/userfiles/file/lajegozizemuti.pdfIn PDF document text
    • https://www.tai.gr/wp-content/plugins/formcraft/file-upload/server/content/files/16140e52174838---33498725443.pdfIn PDF document text
    • https://mcq.bmtinhoc.vn/InteriorWeb/images/images_news/files/89688927997.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=android+make+app+always+runningPDF 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_off0000bc91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC91 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d4a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4A8 11008 bytes
SHA-256: 83d9bfc33814253492e277448f428e4f92585b174df2b2295bb9d8bd33be8ee1
font_02_sfnt_off0000ee08.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE08 16640 bytes
SHA-256: decf9f65daf0c6a7343f0ccb63c4915ba567482c59f8de283be41e45bde580e9