Malicious PDF — malware analysis report

Static analysis result for SHA-256 829a4477d84edb55…

MALICIOUS

PDF

102.2 KB Created: 2021-08-20 11:07:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: e39c5bb5ad244079abbce7b3b215fd25 SHA-1: 143c7372d29da71b24bd36794e1211ef349ac0da SHA-256: 829a4477d84edb551d6b0cabc8581e3451ea2ceba875ee72b18f484d0d6daf33
156 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many pointing to compromised WordPress upload directories or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The presence of multiple external URIs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic confirm the link farm nature of the document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://irlanc.ru/uplcv?utm_term=sistemas+electricos+y+de+seguridad+y+confortabilidad+paraninfo+solucionario PDF link annotation
    • https://www.sibirprokat.ru/ckfinder/userfiles/files/76816681691.pdfIn PDF document text
    • https://xn----8sbaavnccwq4am.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/3c6906ba3c641b6ce56bde196570b542/tilinoderenu.pdfIn PDF document text
    • http://oreade-breche.fr/userfiles/file/11779593444.pdfIn PDF document text
    • http://mrtowing.ca/Lawyers/userfiles/file/46395196173.pdfIn PDF document text
    • http://kag.fr/userfiles/file/gasixobit.pdfIn PDF document text
    • http://witnesstherealist.com/wp-content/plugins/super-forms/uploads/php/files/ed14c6ef608830e8ca6ab19ec301c705/20013404942.pdfIn PDF document text
    • http://pakianco.ir/data/image/uploads/news/files/safidimapozejozaroxukej.pdfIn PDF document text
    • http://www.thediethub.in/wp-content/plugins/formcraft/file-upload/server/content/files/16093a98e7df82---rodemopu.pdfIn PDF document text
    • http://traviet36.com/upload/files/31561859980.pdfIn PDF document text
    • http://bestpokeya.com/uploads/files/jezamogukodufofofajazif.pdfIn PDF document text
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/a3fb7f0faaf17729af65825496c7bc92/3206935672.pdfIn PDF document text
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/ccf4607a2b2d35391adc21c86d6ffa39/94947212841.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1611ea736a934b---pelizuzatojirije.pdfIn PDF document text
    • http://cutencuddlybreedables.com/_images/file/jawakom.pdfIn PDF document text
    • https://www.prowallpanama.com/wp-content/plugins/super-forms/uploads/php/files/4875605c8bd8933b7372865594e3c401/xedigut.pdfIn PDF document text
    • https://kolodezrus.ru/wp-content/plugins/super-forms/uploads/php/files/52aa5c0546f4b7d1746dd0045ae31542/75869542493.pdfIn PDF document text
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/0ne86lh86oon54q9ol9vkmgl57/lewigunipubugolun.pdfIn PDF document text
    • https://www.vibrationmonitoring.asia/wp-content/plugins/formcraft/file-upload/server/content/files/160c21019912eb---mipovadowarosozufog.pdfIn PDF document text
    • https://aslimitada.com/userfiles/file/5257208099.pdfIn PDF document text
    • https://ekaplast.site/admin/ckfinder/userfiles/files/gulexibofudozisara.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/16114421c855e4---navapemekazonexigatu.pdfIn PDF document text
    • http://allivecoat.com/userData/board/file/pafedozagutodisodenu.pdfIn PDF document text
    • http://globaltruthmediagroup.com/clients/a/aa/aa8380eac451876ae6ab993bf3a720d6/File/gizudekuviputivojegawigiv.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_off0001240f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1240F 19044 bytes
SHA-256: bdc8a851d3655a0e808564e084e1609d807297a4c2aa5a88eb1a03500e24e854
font_01_sfnt_off00015484.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15484 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00016c9b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x16C9B 11392 bytes
SHA-256: 507c896bc5c08d2835509336d4ef19e36f98518fe594326b1c6b7e265cc73dac