Malicious PDF — malware analysis report

Static analysis result for SHA-256 3664d320d9e8d95f…

MALICIOUS

PDF

83.2 KB Created: 2021-07-14 01:27:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 2e81e12470bdec56e74bbdc11d1a5ed6 SHA-1: 3b413e82bf9508d36554d804032e80be0b434dfc SHA-256: 3664d320d9e8d95f6f4a9a87d2ec57e50ef993a27629665b0f609d6df3662fd8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF contains a link farm pointing to numerous websites, many of which are hosted on compromised CMS platforms or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The document body is heavily obfuscated and does not provide direct clues, but the presence of numerous external links is the primary indicator of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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 http://uci.ir/userfiles/file/xigupus.pdf In PDF document text
    • http://www.neslihanonur.com/wp-content/plugins/super-forms/uploads/php/files/228be72e78ff20537d30bb18a512236e/34529463117.pdfIn PDF document text
    • http://grafiport.com/userfiles/file/gejabetib.pdfIn PDF document text
    • http://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160a4c1f09466c---fevozirudiz.pdfIn PDF document text
    • https://indobaliart.com/sitefiles/file/42298314025.pdfIn PDF document text
    • http://gayaarchi.com/userfiles/file/20210629191955.pdfIn PDF document text
    • http://bostonmentors.com/userfiles/file/67134808130.pdfIn PDF document text
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ffc3b5fe50---sivufizojabuxi.pdfIn PDF document text
    • https://adbadog.com/wp-content/plugins/super-forms/uploads/php/files/5f97fc6092980b1e2d74a5e0ae577af5/juwisixegu.pdfIn PDF document text
    • https://mojer.bg/files/sofax.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e2dd0c0da70---kuniz.pdfIn PDF document text
    • http://alpha-th.com/userfiles/file/83474660120.pdfIn PDF document text
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076c7d971bfa---wikatolafewuxizetisoza.pdfIn PDF document text
    • http://nessium.net/userfiles/file/litowoteve.pdfIn PDF document text
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/d1df96fc14405513f0f894b74c8fe9a4/9715227071.pdfIn PDF document text
    • http://stagelight.pl/userfiles/files/13882755595.pdfIn PDF document text
    • https://topclassgreenery.nl/images/file/92210108776.pdfIn PDF document text
    • https://mk-sito.it/uploads/file/xinabojub.pdfIn PDF document text
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/ec2570e775df08606bd662d8e8e8c7bd/61567330940.pdfIn PDF document text
    • http://www.olympussverige.se/wp-content/plugins/super-forms/uploads/php/files/15729bj5mf11h52ukfg1l9r9hn/97832000142.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=spring+boot+mvc+interview+questionsPDF link annotation
    • 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_off0000e35c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE35C 11120 bytes
SHA-256: b04f1f7a06e434d09964b145246e7dc96cd4396e8a43b4a916a5fbf0af0d9c55
font_01_sfnt_off0000fcd3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCD3 16196 bytes
SHA-256: 42a66da022941953511d3ccc8e7b1827937ec2e05097b2891020de1143fdba91
font_02_sfnt_off0001261a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1261A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1