Malicious PDF — malware analysis report

Static analysis result for SHA-256 3e4f140944f4fd81…

MALICIOUS

PDF

80.0 KB Created: 2021-09-10 14:50:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: ecb8921197ee8aa4e26d83a12cf56641 SHA-1: 4858b99f38d39afcf0d03b6633b10e30e6de7f62 SHA-256: 3e4f140944f4fd814b48720414cc07fd6ef1db336110faaccfa08fb40741d73d
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically indicating phishing and trojan activity. Numerous embedded URLs point to various domains, many of which appear to be compromised or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' confirms the nature of these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://allytemp.ru/uplcv?utm_term=prednisone+for+vertigo PDF link annotation
    • http://csigikes.hu/admin/fck_upload/file/7204989391.pdfIn PDF document text
    • https://acrgruppe.de/userfiles/file/mofaxodifexirogupasuw.pdfIn PDF document text
    • http://leadershipcareer.kr/fckeditor/_upload/file/16560751862.pdfIn PDF document text
    • https://es21sys.com/userfiles/file/felexijofoxunome.pdfIn PDF document text
    • http://droneducational.com/admin/userfiles/file/52330679233.pdfIn PDF document text
    • https://gadd-asso.org/userfiles/file/tasoginis.pdfIn PDF document text
    • http://phuocthuan.vn/images/pic/file/darofanowojomizevalede.pdfIn PDF document text
    • https://loppisidjupdalen.se/images/uploaded/file/7283335700.pdfIn PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16135d086676c7---pibal.pdfIn PDF document text
    • http://ksiclubbiz.ksiclub.org/svnprojects/DHD/Source/images/files/13081000460.pdfIn PDF document text
    • https://sportnazona.bg/f/uploads/files/45304389307.pdfIn PDF document text
    • http://diagnosticaedilizia.com/userfiles/files/1768221513.pdfIn PDF document text
    • https://patc.fr/imagesfile/pubopebibafobev.pdfIn PDF document text
    • https://ratosatu.com/contents/files/dixuzupudosutivifi.pdfIn PDF document text
    • http://twilaw.com/files/files/durunizewilupu.pdfIn PDF document text
    • http://35ju.21tg.cn/uploadfile/ckeditor/files/vonukowisarota.pdfIn PDF document text
    • http://swhwsolution.it/ckeditor-ckfinder-integration/uploads/files/tesivunutesi.pdfIn PDF document text
    • http://covina.crazyrockinsushi.com/uploads/files/92677732122.pdfIn PDF document text
    • https://aiaciran.org/cache/fck_files/file/wanetifiwiwoziwifuw.pdfIn PDF document text
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613934be5c60b---67432082751.pdfIn PDF document text
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613713da4b243---73536048041.pdfIn PDF document text
    • http://drentmedischadvies.nl/uploads/files/33777155536.pdfIn PDF document text
    • https://joepromenshealth.com/wp-content/plugins/super-forms/uploads/php/files/b96de0c4cc8c7629721df61a449e79b9/2437357260.pdfIn PDF document text
    • https://swalaya.in/userfiles/file/kabanasa.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_off0000d74f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD74F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ef61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF61 17016 bytes
SHA-256: c74bfd381e0309a8b2cba6925601794c17aa190f62ad38c9a62af70dab3d0399
font_02_sfnt_off00011b51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B51 10388 bytes
SHA-256: de2b0c1ccba5ab4dabbd5e87e2ff111554464ecbfd073945b3a619d24d74efad