Malicious PDF — malware analysis report

Static analysis result for SHA-256 c821aaef37d13dcc…

MALICIOUS

PDF

85.0 KB Created: 2021-06-26 01:25:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0517907372c4638aba8f7c3e3696f3c1 SHA-1: 2d5f6138730af6c945feaf663a50a2f0c8e7db66 SHA-256: c821aaef37d13dcc5ef43c595e7a3c5dcb7c970626747bb01ad8bf4e5e8b46b0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous external links, many hosted on compromised WordPress sites, suggesting a link farm designed to redirect users to malicious content. While no scripts were explicitly extracted, the PDF structure and embedded URLs strongly imply an attempt to lead users to phishing pages or download further malware, aligning with spearphishing attachment tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

Heuristics 6

  • 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.
  • 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://catamma.ru/uplcv?utm_term=superwhy+three+little+pigs
    • http://maidichike.com/upload/files/61990782150.pdf
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607b42b153b67---92037994359.pdf
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085a5ebc03d0---66740755833.pdf
    • http://modellszerviz.hu/userfiles/file/somojugirulevaf.pdf
    • http://www.caslyn.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1607506ba1c7d3---43971223869.pdf
    • https://accuratesearch.com/userfiles/file/ledironuwogipulozet.pdf
    • http://www.consorcio.edu.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160c7a97a3cdf3---58479975990.pdf
    • http://www.caribbeandentist.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d7e8ee9cf1---bisadigap.pdf
    • https://www.mii.net/wp-content/plugins/super-forms/uploads/php/files/17a4f2ba467cefe8da5b74cbd0038294/66341872080.pdf
    • http://banlinhkienlaptop.com/userfiles/file/bewuzetowet.pdf
    • https://pointvirgule.ca/upload/editor/file/40772412293.pdf
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a66c49ab73b---munukovisumenumazinukago.pdf
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a06bb796306---75910687216.pdf
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160713c036717c---fidaj.pdf
    • https://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/08fg5libsf6fn215ucqjgr1k3q/34306508082.pdf
    • https://readxyz.org/wp-content/plugins/super-forms/uploads/php/files/88a5fa841caa86934179af8645da60af/ludemilufepajukojofo.pdf
    • http://asesorialuishervas.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4bfa2dc61f---30349935332.pdf
    • http://amghanoi.com/images/ckeditor/files/jodivi.pdf
    • http://trackeg.com/en/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc1dc5e911---49301951863.pdf
    • http://abimobiliare.pl/pliki/File/2910134167.pdf
    • http://www.psstrecno.sk/wp-content/plugins/formcraft/file-upload/server/content/files/160bc0dc8a4419---wajawinegu.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_off0000eae9.bin
15ce1324f7d4f84b4d33ce7260fb4ab5af835ad363df8e7a3f6c0a52a4dfd898
pdf-font-stream PDF embedded font (sfnt) at offset 0xEAE9 10520 bytes
font_01_sfnt_off00010309.bin
4686d6ed84ca369ba9593677ecf571a4ca9a39e402a5fb0d301eea6da3329ee2
pdf-font-stream PDF embedded font (sfnt) at offset 0x10309 16772 bytes
font_02_sfnt_off00012ee5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12EE5 16792 bytes