Malicious PDF — malware analysis report

Static analysis result for SHA-256 4d95fdd62e4bd755…

MALICIOUS

PDF

82.2 KB Created: 2021-09-01 14:58:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 862c25d5c39e7e9e14936c764ade1104 SHA-1: b17381226f8a33cdd8c00cea3a156c576300f8de SHA-256: 4d95fdd62e4bd755046b5a725e2e2c9f977856ff9a128352d658c7f3bbaf7c01
96 Risk Score

Malware Insights

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

The ML classifier strongly indicated maliciousness, supported by heuristics identifying the PDF as a link farm pointing to compromised or disposable hosting. The document body is heavily obfuscated and unreadable, suggesting an attempt to hide its true purpose. The numerous embedded URLs, many hosted on suspicious domains, are the primary indicators of malicious activity, likely serving as redirects to malicious sites or for SEO spam.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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://1utilaje.ro/mm/file/74297668661.pdf
    • http://jfhconsultancy.nl/userfiles/files/28780694738.pdf
    • https://ascinfratech.com/clientprojects/trading/file/mapepunovites.pdf
    • http://sjar-tech.com/uploadfile/file///2021082207203432.pdf
    • https://www.traveltimevipp.com/wp-content/plugins/super-forms/uploads/php/files/10038ee1032f7af63fbff68427fe8bb5/79573837024.pdf
    • https://zevkotodoseme.com/upload/ckfinder/files/zisoxofu.pdf
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/1609c71be6c693---wunimowupojiderugobidema.pdf
    • http://alvasari.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3006d60ee5---punifef.pdf
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/653fcb76fa0772f057a49b3e55a5ec57/newowodupameforaburadoja.pdf
    • http://plncse.hu/php_data/file/2044948584.pdf
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files//kinerosomopaveziguzubawos.pdf
    • https://eetravel.net/file/satapazesogominesesoxo.pdf
    • https://hnhaa.com/userfiles/tnejp//files/xobisumeruw.pdf
    • http://alibabashipping.com/userfiles/file/tadaxodu.pdf
    • http://trungtinjsc.vn/upload/FCK/file/54274876485.pdf
    • http://www.fotografoeventimilano.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076b01b6569e---wujaminegozowakalev.pdf
    • http://africanhairbraidingsalon.com/userfiles/file/femaxorajew.pdf
    • http://abwingsbuffalo.com/uploads/files/83404527754.pdf
    • http://bergfin.se/wp-content/plugins/formcraft/file-upload/server/content/files/1608e87cd7bfdb---lesebobonesapemuroxu.pdf
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/724caeb12da7a57c8211273265dc778f/51421399290.pdf
    • https://comesa.com.pe/wp-content/plugins/super-forms/uploads/php/files/2o1inm35a42gukqkgd7lom4sc3/49828896032.pdf
    • https://vcvscr.cz/www/www/fckphotos/file/64729136724.pdf
    • http://w-f-l.de/user_img/file/tarurogewukap.pdf
    • http://cbelmira.com/wp-content/plugins/super-forms/uploads/php/files/gtcivqbpeqk72dq2n26ptdr9k5/wonajo.pdf
    • https://seroinstitute.com/wp-content/plugins/super-forms/uploads/php/files/f62ffd7f5106cac744180d97b6a69be6/29111599387.pdf
    • https://loskutova.site/wp-content/plugins/super-forms/uploads/php/files/4ec00e81bb5cd80e61e7f4b3c5ae0cf8/vunojapitemozexavez.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=applied+differential+equations+pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d967.bin
56d8011c489a540db116010928cca99dcf78ffdfae270921c3e75ccba3081f81
pdf-font-stream PDF embedded font (sfnt) at offset 0xD967 19020 bytes
font_01_sfnt_off00010ab8.bin
f738bd546c84552fc718962bbe6e55bfdf55e945df3a8224d67e3d1f4ef329ef
pdf-font-stream PDF embedded font (sfnt) at offset 0x10AB8 10716 bytes
font_02_sfnt_off00012339.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12339 16792 bytes