Malicious PDF — malware analysis report

Static analysis result for SHA-256 71e1bad1e2733b82…

MALICIOUS

PDF

74.6 KB Created: 2021-09-16 07:30:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: a2505bf1af86f816a689fd0d1281e46b SHA-1: 4adc6c7c2cb458862d382176cc2d1caa6780b8b1 SHA-256: 71e1bad1e2733b8273327335a8efb9ae35566bab04e549f53741fcf45280425f
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains embedded JavaScript, a common technique for executing malicious code within PDFs. The presence of numerous external links, some pointing to compromised WordPress sites, suggests a redirection mechanism likely used for phishing or to download further payloads. The document body is heavily obfuscated and unreadable, further supporting a malicious purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9907

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • 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://cremeconferences.com/wp-content/plugins/super-forms/uploads/php/files/f597d56948d0e818eee4617e16a28f0a/13448776683.pdf In PDF document text
    • https://gosselindesign.com/images/from_fckeditor/fichiers/59307302856.pdfIn PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613782180ab79---wigukegafenitusoxed.pdfIn PDF document text
    • https://onutglen.com/caningest/images/file/84844927951.pdfIn PDF document text
    • http://galluccifaibano.com/userfiles/file/16036895344.pdfIn PDF document text
    • https://interativacorretora.com/fotosempresa/files/wemuwedowakap.pdfIn PDF document text
    • http://westernmaki.com/uploads/files/sadedirutabetil.pdfIn PDF document text
    • https://jordan.si/dokumenti/file/kavitov.pdfIn PDF document text
    • https://mentormedya.com/files/rovavodo.pdfIn PDF document text
    • http://langeline.com/ckeditor/upload/files/80601889111.pdfIn PDF document text
    • http://galantemontagnana.it/ckfinder/userfiles/files/kakesirinonemakudakep.pdfIn PDF document text
    • http://garagehayashi.com/js/upload/files/pokerozebomakefaguginifun.pdfIn PDF document text
    • http://energo-market.ru/sadm_files/73742172699.pdfIn PDF document text
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/4locssk1g7vmvq35pmi5fjg821/81366166404.pdfIn PDF document text
    • http://oilspecchem.com/files/96946002464.pdfIn PDF document text
    • http://scenekunstskolen-efteruddannelsen.dk/ckfinder/userfiles/files/3549489300.pdfIn PDF document text
    • http://quimicahj.com/admin/userfiles/userfiles/file/5759974918.pdfIn PDF document text
    • https://californiaoptionsrealestate.com/wp-content/plugins/super-forms/uploads/php/files/65b5ba4d7ead8bfd393c628582cbf864/piteken.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613720ab24158---fefab.pdfIn PDF document text
    • http://www.pantonerestauri.com/ckfinder/userfiles/files/36214536203.pdfIn PDF document text
    • http://slesnick.net/userfiles/files/zupogufavu.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/b839da3f90890f7b05fd2ea3aea7eaca/dezegagegosipug.pdfIn PDF document text
    • https://khonggiansachhanoi.vn/uploads/files/tuzolidovofapajuw.pdfIn PDF document text
    • https://o-dance.com/upload/files/41653575293.pdfIn PDF document text
    • http://www.armstrongre.com/files/files/ronebutofoveromenovobomop.pdfIn PDF document text
    • https://sierrainstruments.cn/fckeditor/editor/filemanager/connectors/php/fckeditor/upload/202109/file/8276508900.pdfIn PDF document text
    • http://specialcats.nl/media/files/54446011487.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=conversaciones+escritas+pdfPDF 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_off0000c0ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC0EC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d8fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8FE 17020 bytes
SHA-256: c7f7eaf90c593ea45561432801c3fceb72932899d4739def3f039f72f7f73925
font_02_sfnt_off000103c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103C6 10664 bytes
SHA-256: 1ae00050bc80c8d9c3b862cd1a0be6f5fb4b3e402d6848f4ec0eba7c57c327f7