Malicious PDF — malware analysis report

Static analysis result for SHA-256 99e8c8dd19072a96…

MALICIOUS

PDF

80.6 KB Created: 2021-09-03 10:29:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 2fa17516e789496f796455fdab83cf3e SHA-1: 8eb87f6d5dbb20515491a8f60fa1a7c412b9236e SHA-256: 99e8c8dd19072a96ef9947b4c3a92dab947d6357b5e7ccc45d7e997c76d616d2
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file is identified as malicious by multiple heuristics and a machine learning classifier, including ClamAV detection. It functions as a link farm, directing users to compromised WordPress sites and disposable hosting domains, likely to facilitate the download of further malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics indicates a tactic to distribute payloads through seemingly legitimate but compromised infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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=indicadores+de+calidad+y+productividad+pdf
    • http://yngc.ru/admin/ckfinder/userfiles/files/kusovanadewotuviweful.pdf
    • http://cbcom.eu/ressource/site-image/files/teredi.pdf
    • https://remoteworkerclub.com/wp-content/plugins/super-forms/uploads/php/files/7152cd010d6b464de98fd85823503c6a/kofilakopadugaj.pdf
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608f8eb20ced7---tenuludobonof.pdf
    • http://thermogroup.ru/uploads/files/61352484391.pdf
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/c3379fce4903cfe48fa701c37e42b48c/66820812387.pdf
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/dic9jepd88okl7ca97mjrf7qk7/xawamiduri.pdf
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609b9e17e5060---pudixiviwoguzop.pdf
    • http://christembassydocklands.org/wp-content/plugins/super-forms/uploads/php/files/370cac920ee5d12b81e8af17860a1ee6/68577920873.pdf
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/160e2e0e862d7b---jijubusafibu.pdf
    • http://blevy.com/ckfinder/userfiles/files/36828053267.pdf
    • http://esenkardeslerinsaat.com/resimlerfiles/75868263640.pdf
    • http://studio-castiglioni.com/userfiles/files/nofaroxiludipulunazaf.pdf
    • http://hytechplus.com/userfiles/file/fenovidijosanuzu.pdf
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/1609b180ebf837---kejonifa.pdf
    • https://thewentworthco.com/wp-content/plugins/super-forms/uploads/php/files/646d9aonpg44thbu06c8url22l/41494011927.pdf
    • http://rajasthanmetals.com/userfiles/file/kugavutobafigaxe.pdf
    • http://atthaya.com/file_media/file_image/file/nipenetufudajejiz.pdf
    • https://smartmedia.ro/app/webroot/files/userfiles/files/kugelunezafevu.pdf
    • https://maviet.vn/upload/files/45957251249.pdf
    • https://indobaliart.com/sitefiles/file/77888551402.pdf
    • http://www.advokat.com/app/webroot/img/fck/file/71614489161.pdf
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fe9aa06cb2---32844979592.pdf
    • http://guowangcable.com/d/files/41612171182.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_off0000d505.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD505 16792 bytes
font_01_sfnt_off0000ed17.bin
918fdcf29df749d8323a930d05b640d7e8653df3dbcc9e630e7423323d01994c
pdf-font-stream PDF embedded font (sfnt) at offset 0xED17 18416 bytes
font_02_sfnt_off00011bb9.bin
dfec32fb329c7bc5b8f33ffde14e178ea4a9ccbe4b1910f073023c9d9fb3d57d
pdf-font-stream PDF embedded font (sfnt) at offset 0x11BB9 10844 bytes