Malicious PDF — malware analysis report

Static analysis result for SHA-256 f55fb945e9725dab…

MALICIOUS

PDF

71.0 KB Created: 2021-09-25 23:35:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 55eb8ca2f40e8e865abec35214d9bddd SHA-1: 3a318a7e1a3017576bb2932a04cea2d65c3ebf70 SHA-256: f55fb945e9725dabb2841638d952503a2bd65efdcc0dfa5bb7e6635cf03496b5
156 Risk Score

Malware Insights

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

The PDF contains numerous external URIs and links to compromised WordPress upload storage, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The presence of multiple compromised CMS upload links points to a tactic of leveraging vulnerable websites for hosting malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://smidgel.ru/uplcv?utm_term=pokemon+shiny+gold+cheats+pokemon+modifier PDF link annotation
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e3487082c8---zometelosidugegunu.pdfIn PDF document text
    • https://www.luthier-auxerre.fr/ckfinder/userfiles/files/69957305371.pdfIn PDF document text
    • http://thuephotocopytaihanoi.com/upload/files/18639211661.pdfIn PDF document text
    • http://vinhthuan.com/upload/files/651046755.pdfIn PDF document text
    • http://consorzio-csa.it/userfiles/files/xuzorof.pdfIn PDF document text
    • http://obchodsezlatem.cz/upload/files/rojojolulakoxulare.pdfIn PDF document text
    • http://gerastar.com/userfiles/file/teporigagawig.pdfIn PDF document text
    • http://chinajnbt.com/images/upload/File/97405502682.pdfIn PDF document text
    • http://librojuridico.com/aym_images/files/gelawaxabenejilezaresuze.pdfIn PDF document text
    • http://mcenterdk.ru/fck_editor_files/files/62149550826.pdfIn PDF document text
    • http://momsystem.ru/public/file/torafagekifema.pdfIn PDF document text
    • https://www.borzabadi.com/ckfinder/userfiles/files/82113622458.pdfIn PDF document text
    • http://alsace.annuaire-regional.com/ckfinder/userfiles/files/59647268655.pdfIn PDF document text
    • http://biirbeh.mn/images/content/file/sulobazubidajator.pdfIn PDF document text
    • http://crystal-lamp.ru/uploads/files/4926682622.pdfIn PDF document text
    • http://ventmetal.ru/userfiles/files/19909310526.pdfIn PDF document text
    • http://cedresarquitectura.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134a9fa540a0---jetokajasokowof.pdfIn PDF document text
    • http://www.ettermanenterprises.com/ckfinder/userfiles/files/73938113733.pdfIn PDF document text
    • http://euskararenginkana.eus/files/galeria/files/19204048737.pdfIn PDF document text
    • http://studiopol.com/userfiles/files/59230337396.pdfIn PDF document text
    • https://tavio.ru/files/file/73085643093.pdfIn PDF document text
    • http://www.jcca.co.in/wp-content/plugins/formcraft/file-upload/server/content/files/16138cc70dc736---176028384.pdfIn PDF document text
    • http://sartor.ru/upload/files/37189058085.pdfIn PDF document text
    • http://hcbarrett.com/user_area/file/manipevetevixogisigupu.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_off0000b18b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB18B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c9a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9A2 11272 bytes
SHA-256: 6bafbea68a083673eb4b47698b0298d792bce3dd601e0c5a46bbfbc6bb336880
font_02_sfnt_off0000e3ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3BA 16848 bytes
SHA-256: b0dcbf5ca9e8f45e30199a5715020ad3b25b93843cb91d1f97a94fd8e61d4015