Malicious PDF — malware analysis report

Static analysis result for SHA-256 66dc60f6dd653c09…

MALICIOUS

PDF

86.6 KB Created: 2021-08-11 04:55:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-18
MD5: a1944ff309768613c22bd08d75e8b74d SHA-1: d7f7e7630971cbacb053e5394fde7bc3c6407967 SHA-256: 66dc60f6dd653c098146af875cda0a5afddd209b1030456f4dc179234db765d7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to distribute malicious content or phish users. The ClamAV detection and ML classifier strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are consistent with techniques used to deliver second-stage payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://allytemp.ru/uplcv?utm_term=integrated+grammar+practice+for+class+5 PDF link annotation
    • http://penoplex24.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160914b693d8ec---votofuni.pdfIn PDF document text
    • http://lavalnerina.it/userfiles/file/nijotebapodaw.pdfIn PDF document text
    • http://msamericapageant.com/clients/873634/File/44812104511.pdfIn PDF document text
    • http://www.patriarca-batiment.com/ressource/site-image/files/86964922728.pdfIn PDF document text
    • https://emotionalgift.com/ckfinder/userfiles/files/97774518992.pdfIn PDF document text
    • http://mploa.com/clients/2/2c/2ccb326c3583e393996f575e36ee3974/File/xiwijuzi.pdfIn PDF document text
    • http://kiuruvedenlukio.fi/tiedostot/file/50892047849.pdfIn PDF document text
    • https://www.rockandroll.blog.br/wp-content/plugins/super-forms/uploads/php/files/j580pv9pt2agu7sff79s6ofqk5/megusiwenasojafesap.pdfIn PDF document text
    • https://xn--faades-mtal-n9a6a.ch/ckfinder/userfiles/files/95805934151.pdfIn PDF document text
    • https://digireg.ch/upload/35443163959.pdfIn PDF document text
    • https://samngaimarble.com/html_upload/file/zumevaketirosixetedi.pdfIn PDF document text
    • http://www.findvoters.com/userfiles/file/garumodexixebofi.pdfIn PDF document text
    • https://ka-base.no/images_students/files/23050252103.pdfIn PDF document text
    • https://inchiriereelicopterromania.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160cdfd313756a---sinonixuzatipot.pdfIn PDF document text
    • https://moniimpex.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f52fced18a5---34190769618.pdfIn PDF document text
    • https://www.yoursurveysurveyors.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a518b275a64---63705026907.pdfIn PDF document text
    • http://raduzhniy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d954e137cc---76556997073.pdfIn PDF document text
    • https://apoc.com.au/wp-content/plugins/super-forms/uploads/php/files/894f0ddcc2f77bef06e9631885f35d2a/67967727833.pdfIn PDF document text
    • 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_off0000ed0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED0F 17372 bytes
SHA-256: 3e4f1bc12fd691368e8f74e599e1dc979f3d29b511c3da215de056e85b578e7d
font_01_sfnt_off00011a5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A5B 11048 bytes
SHA-256: f2d0d59cdc81f9d2944897ff05e79659a7e0f7ccb46390af5dd5bec477865c51
font_02_sfnt_off000133dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x133DC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1