Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa755c7bb89fea69…

MALICIOUS

PDF

77.7 KB Created: 2021-08-29 04:59:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 7fc575e9a9fc9264b2ec3d5596992419 SHA-1: 31177ed561ab431283eafa93f71a458f9d92d40e SHA-256: aa755c7bb89fea694884e9c8dc41a78ad7fa3674e2dbeb05eb9b3ba0c746c5d9
96 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users. The ML classifier strongly flagged this PDF as malicious. While no scripts were extracted, the structure and embedded URLs suggest an attempt to lead users to malicious sites, potentially for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://gld-lining.com/user_img/files/84349522011.pdf In PDF document text
    • https://harpethvalleypto.org/wp-content/plugins/super-forms/uploads/php/files/287fe32f8dad4fd084a6a997601171c4/68913839639.pdfIn PDF document text
    • https://angkorphotographyguide.com/userfiles/file/mepivarozufonanururibuw.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/1609439688f149---dobesabosarufefabiwiwit.pdfIn PDF document text
    • http://rideabikenews.com/user_img/files/madut.pdfIn PDF document text
    • http://saaretravel.ee/images/file/ruziwexosobuxo.pdfIn PDF document text
    • http://xn--72c7caerxx0d3a9eve.com/UserFiles/File/rutovujujorewimoxolew.pdfIn PDF document text
    • https://functionalmovement.gr/wp-content/plugins/super-forms/uploads/php/files/b622c7b6174dba79fe617ba0aa0550c5/fanemorutarowebigisowir.pdfIn PDF document text
    • http://www.advokat.com/app/webroot/img/fck/file/tewogubakixubokojitafud.pdfIn PDF document text
    • http://architects-desk.com/uploadsfile/tutuvilufudibedunepiti.pdfIn PDF document text
    • http://abwva.com/uploads/files/65305892258.pdfIn PDF document text
    • http://jrpst.pl/userfiles/file/nanojulatimujex.pdfIn PDF document text
    • https://varbackaforskola.se/ckfinder/userfiles/files/98296132699.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160df482f6bd9f---soxinawuloni.pdfIn PDF document text
    • http://neuragen.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607e6383a28fc---3937999229.pdfIn PDF document text
    • https://jesssmithtri.com/jesssmith/ckfinder/userfiles/files/nowaziduvepusebabefo.pdfIn PDF document text
    • http://www.autoservis-hubatka.cz/admin/upload/ww/file/45926108323.pdfIn PDF document text
    • http://sosnovgeo.ru/userfiles/file/75277405487.pdfIn PDF document text
    • http://haus-st-otmar.ch/userfiles/files/faxegokuvezexesu.pdfIn PDF document text
    • https://extremetour74.ru/wp-content/plugins/super-forms/uploads/php/files/fe0d7d6a53ab3a5a10c4e20fb529b0e0/nozevilagasoluziwi.pdfIn PDF document text
    • http://amirmazandaranihospital.com/ckeditor/files/files/46171245653.pdfIn PDF document text
    • https://confetti-seasons.ru/upload/files/76911953295.pdfIn PDF document text
    • https://mvmdigital.gr/files/files/xerivubojaviwigovadil.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=3am+thoughts+quotesPDF 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_off0000c9a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9A9 10532 bytes
SHA-256: 1b6d520efb6aa2ba0d500f83a83305dde3bedfd14d7a8756144e87730f4049fc
font_01_sfnt_off0000e16a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE16A 17904 bytes
SHA-256: 0b30abd08da24a667d7b9217937951c69340e793f841b5bf4106136977ba60eb
font_02_sfnt_off00010fb6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FB6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1