Malicious PDF — malware analysis report

Static analysis result for SHA-256 6431f679f8f8b94a…

MALICIOUS

PDF

88.4 KB Created: 2021-08-05 19:02:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 258e24115bdb7436efb7acc5dda27aa2 SHA-1: 733a61716cfc60f3cb97d5f99fc1b75a8cf6d328 SHA-256: 6431f679f8f8b94aa715ecd12381421cb9390814d755223b6f0b9e9869bba599
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous external links, many pointing to compromised WordPress upload directories and disposable hosting, indicating a link farm designed to manipulate search engine results or distribute further payloads. ClamAV and ML classifiers strongly indicate malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are consistent with a malicious PDF dropper.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://manuscripthandler.com/userfiles/file/2122592740.pdf In PDF document text
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/hfgic4e56u8ehm1nk3bgq1oai1/luzipogiwutuzuponop.pdfIn PDF document text
    • http://ccforum.kr/uploads/file/1621483639.pdfIn PDF document text
    • https://webtraffic.ch/wp-content/plugins/super-forms/uploads/php/files/qoap09on57555n116a028h127v/22687188735.pdfIn PDF document text
    • https://luxmarketing.agency/wp-content/plugins/super-forms/uploads/php/files/qhrcj5bee6v18q0oa1o2aei735/fotamagevuxoje.pdfIn PDF document text
    • https://churchosonline.com/wp-content/plugins/super-forms/uploads/php/files/1d2c594f4a1fe1b509e51392cdfdf216/98501808171.pdfIn PDF document text
    • https://lawyerupsmart.com/tempimg/file/84135997477.pdfIn PDF document text
    • http://nail-free.com/ckfinder/userfiles/files/sumex.pdfIn PDF document text
    • http://gnatowski.pl/attachments/file/67202956194.pdfIn PDF document text
    • http://topcudental.com/img/userfiles/files/linotanivalefarajibero.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/dd8d08ec21e24c3bd70966667025a57b/pasoxadanan.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/ce548dcd7e5638aebab80caac3933cb4/gojisebevosixufepe.pdfIn PDF document text
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/1608b7a106c4ea---zomojibarapojidojepunomis.pdfIn PDF document text
    • http://ebslang.net/_UploadFile/Images/file/27700226320.pdfIn PDF document text
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092180e504a6---1854094203.pdfIn PDF document text
    • http://rickgrisolia.com/userfiles/files/koxamore.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f54e3316b15---8316828145.pdfIn PDF document text
    • http://writtenmail.com/upload_images/file/varodutirexixomiwi.pdfIn PDF document text
    • https://www.golddustdental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a986c84e6dd---bapomekimodefabovevaj.pdfIn PDF document text
    • https://cuacuonbentre.com/upload/files/68869616624.pdfIn PDF document text
    • http://thesnowmanicecream.com/ckfinder/userfiles/files/6070638869.pdfIn PDF document text
    • http://ajtoablakcentrum.com/_user/file/gisosow.pdfIn PDF document text
    • http://aromamahabaleshwar.com/ckfinder/userfiles/files/lefugerapalipozetizagutu.pdfIn PDF document text
    • https://technok.cz/wp-content/plugins/super-forms/uploads/php/files/544a0ca4c6b9159723e1e785f4d55cde/27649741225.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=bearcat+chipper+sc3305+manualPDF 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_off0000f738.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF738 11100 bytes
SHA-256: 32ce921d272d0d7cdd1c139f506dc70d32e75fdf11ec7af9d8125f45360443ef
font_01_sfnt_off000110fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110FD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001290f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1290F 16392 bytes
SHA-256: 655a894c0f37501501bcb8e52bd23ac53f19adf5d23d1e37ebdae2762922401e