Malicious PDF — malware analysis report

Static analysis result for SHA-256 0645cc9c04d16b42…

MALICIOUS

PDF

71.9 KB Created: 2021-09-08 03:44:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 4acc41ce5817b82bb367c187e42f5d2d SHA-1: db7ba35c2db3860595a34b7d1d3e0bcc31b19780 SHA-256: 0645cc9c04d16b4249f16aa984bbe73128d13b8831effc77e8292d8c2c3aae31
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to compromised or disposable domains, indicating a link farm designed to redirect users. Heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' strongly suggest a malicious intent, likely for phishing or distributing further malware. The ML classifier and ClamAV detection further confirm the malicious nature of the file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://smidgel.ru/uplcv?utm_term=que+es+un+ensayo+argumentativo+pdf PDF link annotation
    • https://oteaexpert.fr/cite_imgs/file/nedibegilawij.pdfIn PDF document text
    • http://mastrodibaglio.it/userfiles/files/vuxosusomakufegitokuxew.pdfIn PDF document text
    • http://www.tiande-global.com/ckfinder/userfiles/files/13564093982.pdfIn PDF document text
    • http://okfilm.kr/userData/board/file/zasabomoz.pdfIn PDF document text
    • http://nppgursaraijhansi.in/ckfinder/userfiles/files/jodifesefuma.pdfIn PDF document text
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160f4dc5f95ea4---bufepa.pdfIn PDF document text
    • https://anakaygame.net/calisma2/files/uploads/mabowowuxudofikid.pdfIn PDF document text
    • https://web-sila.ru/wp-content/plugins/super-forms/uploads/php/files/89e8f67e2cfb9e2b750dae42e56ddb35/dovodiwetaz.pdfIn PDF document text
    • http://zespolbahamas.pl/zdjecia/file/dadijovaka.pdfIn PDF document text
    • http://ukrainski-rosyjski.pl/userfiles/file/83750774151.pdfIn PDF document text
    • http://wisdomtours.net/upload/file/famabasixoj.pdfIn PDF document text
    • http://visit-pune.com/userfiles/file/2626939216.pdfIn PDF document text
    • http://globeksa.com/ckfinder/userfiles/files/49155931515.pdfIn PDF document text
    • https://mtmnetwork.net/uploadEditor/files/gusuvodoz.pdfIn PDF document text
    • https://mymovingestimate.com/wp-content/plugins/super-forms/uploads/php/files/3dd446f654d38797697bbac20406467a/33994939621.pdfIn PDF document text
    • https://xehowo24h.com/images/ckeditor/files/xefonexidexupawiposuzobi.pdfIn PDF document text
    • http://artin-intranet.com/ckupload/files/vokazaxulopipenosiropat.pdfIn PDF document text
    • http://orchid-daikanyama.com/userfiles/file/kekafemidinow.pdfIn PDF document text
    • http://clearspace-design.com/CKEdit/upload/files/todirujemupunobonubat.pdfIn PDF document text
    • https://dalnoboy.com/data/filestorage/upload/files/kolarizasikobuzeman.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_off0000b64f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB64F 11132 bytes
SHA-256: ac2b60d60ef3062d9746cbc4d983adcd9655b4ea040bb52184d393709d498728
font_01_sfnt_off0000d045.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD045 16796 bytes
SHA-256: 1fe636e9198cd916e5923be6aeb90ad6aa94ca2700498995d801826809d292b8
font_02_sfnt_off0000fa6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA6B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1