Malicious PDF — malware analysis report

Static analysis result for SHA-256 548a41b9f3c14993…

MALICIOUS

PDF

94.9 KB Created: 2021-09-06 02:15:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 91c42560b44f9854fb7320664b35e0a5 SHA-1: d4279abf35e1cb9d167dfa80230c21a5ba446859 SHA-256: 548a41b9f3c14993b7e25f6a27cb98e0d1c164d21f93aa0467a86c37ad91186c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains numerous links pointing to compromised WordPress sites and disposable domains, indicative of a link farm used for phishing or malware distribution. The ClamAV detection and ML classifier strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are sufficient to infer a malicious link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9820

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://nomylo.ru/uplcv?utm_term=ttl+logic+family+characteristics+pdf PDF link annotation
    • http://radio-salsa.com/php/rs/filesupload/file/mofijizaguzofumadivaxif.pdfIn PDF document text
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609642e7f127e---76126417787.pdfIn PDF document text
    • http://admio.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1606f8bd1c312d---fijawasanugixabalolewid.pdfIn PDF document text
    • http://ciarajewellery.com/editor_upload/file/43636670985.pdfIn PDF document text
    • http://ideviceplus.be/app/webroot/files/userfiles/files/49419010069.pdfIn PDF document text
    • https://ecoverservice.be/gallery/file/44627102777.pdfIn PDF document text
    • https://www.limratechnologies.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609866d37a9ce---rokosojeboxenewevar.pdfIn PDF document text
    • https://www.lightingsolutionsinc.net/wp-content/plugins/super-forms/uploads/php/files/d8c28642e97743991e46885a16203f4b/8309515763.pdfIn PDF document text
    • http://videoacceso.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cd6c9cee97---56045971978.pdfIn PDF document text
    • http://interreg-ipa-husrb.com/downloads/31757805568.pdfIn PDF document text
    • http://ural-resyrs.ru/data/file/dijetidodokurimozo.pdfIn PDF document text
    • https://www.la-providence-ehpad.fr/ckfinder/userfiles/files/81495541433.pdfIn PDF document text
    • http://e-kva.ru/admin/ckfinder/userfiles/files/jupobusufovujuwof.pdfIn PDF document text
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/eebc44ba972697b9cb911a02ee4c6498/33168558581.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/mn9fld1ug834a59ibqmnume792/52564738437.pdfIn PDF document text
    • http://ttccid.com/userfiles/file/63051405008.pdfIn PDF document text
    • https://danfort.lv/userfiles/file/pilanilupavisakawek.pdfIn PDF document text
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/arogkk2i1esrrfv1an226du2j9/77944584458.pdfIn PDF document text
    • http://alpha-cp.com/userfiles/file/ropap.pdfIn PDF document text
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/16121a37a40acc---zetuzowezutor.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160ad70c7264c6---50141953127.pdfIn PDF document text
    • http://fine-trading-knotwork.de/uploads/media/24486923334.pdfIn PDF document text
    • http://train-in-japan.com/images/blog//file/xuzuzavaxeseben.pdfIn PDF document text
    • http://bartuceviri.com/userfiles/file/56015929360.pdfIn PDF document text
    • https://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160b3c39e5d0cb---20660903504.pdfIn PDF document text
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/768482406e10c7909ac179adb506a0d2/xomiw.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_off00010c9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C9E 11040 bytes
SHA-256: 8a2179db68c7bc599926c674a65914c54f2da67018473c9833186bf49073d567
font_01_sfnt_off0001262a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1262A 18336 bytes
SHA-256: 7dd625029c25c7ecc5c35b79e29b0ec6f692e94a9cdf5ca498bcbebbe31bd52d
font_02_sfnt_off000155f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x155F4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1