Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8607e5457c5523f…

MALICIOUS

PDF

69.6 KB Created: 2021-06-09 10:06:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-01
MD5: b355205b88fdd9a89609f464b8ce8120 SHA-1: 1fdbbd62f98c6eb328494b6d41f9492c5b0e1003 SHA-256: c8607e5457c5523f4688d444cc583796a920a2031466b0c6fc2a7e51dcf4331c
104 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://nomylo.ru/uplcv?utm_term=asi+se+dice+level+2+workbook+pdf+answers PDF link annotation
    • https://halobysciton.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ac91a831da---18494136488.pdfIn PDF document text
    • https://www.medipratik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7d71cca26---50713726236.pdfIn PDF document text
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b205edb2d92---poxugaxabirelewirorab.pdfIn PDF document text
    • https://xn--64-mlcufjjaii0l.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/a50d234260231509b244af1396e95a1d/49760964571.pdfIn PDF document text
    • http://beulahcooleycollection.com/clients/870349/File/lafitivadadanerinavivene.pdfIn PDF document text
    • http://sportgalaktik.sk/userfiles/file/47872565782.pdfIn PDF document text
    • https://glasschneider.koeln/wp-content/plugins/super-forms/uploads/php/files/tb4dtetrgi3bn53kgf9889tgv6/13052920300.pdfIn PDF document text
    • http://aaykpn.com/uploads/editor/files/sexasiwo.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/rdfe3ip3ak05ka8gqvioq918l4/24521284879.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/tesav.pdfIn PDF document text
    • http://goref.ru/files/file/fodipev.pdfIn PDF document text
    • https://www.oneirishrover.com/wp-content/plugins/super-forms/uploads/php/files/1e8095ec70db96055ed37020b9ada11a/7165267109.pdfIn PDF document text
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f23f2b195a---refupivujovimobopo.pdfIn PDF document text
    • http://amon-syotengai.com/userfiles/file/66498901573.pdfIn PDF document text
    • https://electrabicycles.pl/app/webroot/uploads/file/16209506047817.pdfIn PDF document text
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ababebc9b08---nurokubev.pdfIn PDF document text
    • https://www.properties-thassos.com/wp-content/plugins/super-forms/uploads/php/files/fbngbn0qfvp437m931l95hlqam/gamefudawodisufitawomi.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c42b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC42B 5336 bytes
SHA-256: 496a9274466a71f2b70ece31a65553276dc6c65152223f2872bce39b7be59d7e
font_01_sfnt_off0000d65e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD65E 10800 bytes
SHA-256: b7644350748948f7dacdea4c1f3d3ed34a69d19374a9d980d954629531562a73
font_02_sfnt_off0000fb41.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB41 4324 bytes
SHA-256: 1062cd8ddf90f4344fa193b395386d5669df1a952e5759311ca261a71931f361