Malicious PDF — malware analysis report

Static analysis result for SHA-256 1a49c0cbe8c23a1c…

MALICIOUS

PDF

68.7 KB Created: 2021-10-01 02:38:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 89a9a11c78c746e2afe91d48a5496f59 SHA-1: 3b40623a0ff149b622739bd9ff71166b64a3d598 SHA-256: 1a49c0cbe8c23a1c67b65b7a1c3881c44a4e747b47f4eaf4d4185df1ded75053
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file is identified as malicious by ClamAV and an ML classifier, with multiple heuristics indicating it functions as a link farm. The embedded URLs point to various domains, many of which appear to be compromised or disposable hosting, suggesting an attempt to distribute malicious content or conduct phishing. The document body is heavily obfuscated and contains metadata from wkhtmltopdf, indicating it was likely generated programmatically to host these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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://infrive.ru/uplcv?utm_term=kotlin+apprentice+pdf PDF link annotation
    • http://mtecommerce.it/public/news/file/88067702161.pdfIn PDF document text
    • http://bilagroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/161460bb954ce7---puvironevaw.pdfIn PDF document text
    • https://riwg.in/userfiles/file/33581075772.pdfIn PDF document text
    • http://ziguratex.com/helpdesk/app/webroot/img/userfiles/files/bugimo.pdfIn PDF document text
    • https://akemi.ro/hirek/file/98240442999.pdfIn PDF document text
    • http://libertyquad72.fr/userfiles/file/vudubon.pdfIn PDF document text
    • http://gpe-el.pro/ckfinder/userfiles/files/94669963363.pdfIn PDF document text
    • http://1000projects.ru/upload_picture/file/biwezetavufaz.pdfIn PDF document text
    • http://www.sindafaz.com.br/admin/editor/ckfinder/userfiles/files/xezuw.pdfIn PDF document text
    • http://webinaris.net/ckfinder/userfiles/publics/files/23325801183.pdfIn PDF document text
    • https://jancsoalapitvany.hu/ckfinder/userfiles/files/44260466125.pdfIn PDF document text
    • http://tlumacz-francuskiego.pl/userfiles/file/witulakipodefajuf.pdfIn PDF document text
    • https://www.domaine-vrignaud.com/ckfinder/userfiles/files/zafugewi.pdfIn PDF document text
    • http://mateuszkucharski.pl/admin/file/foseraxibawo.pdfIn PDF document text
    • https://brianhigbielaw.com/UserFiles/file/33344947737.pdfIn PDF document text
    • https://kovrdom.ru/sites/all/sites/default/files/file/kupokirinotedebo.pdfIn PDF document text
    • https://www.sevgiliyevideo.net/wp-content/plugins/formcraft/file-upload/server/content/files/161543790be12a---suzefudurugete.pdfIn PDF document text
    • https://indicaperu.com/userfiles/file/gutewuvenifijonan.pdfIn PDF document text
    • http://nova-auto.com/upload/27384433427.pdfIn PDF document text
    • http://beautifulmoda.com/userfiles/files/68863837895.pdfIn PDF document text
    • https://bkairconditioner.cloud4demo.com/uploads/files/wekezuwomat.pdfIn PDF document text
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16152d09d12912---58608341451.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_off0000addc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xADDC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c5ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC5EE 15692 bytes
SHA-256: 36d6e9560f971f1e4fc9ca8889659071713b3235a54332dd576844516adf2102
font_02_sfnt_off0000eddf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDDF 10436 bytes
SHA-256: 25646191edd8348591caaf95f44e172db36a61caeef878a1f075afc1fb2ed4b2