Malicious PDF — malware analysis report

Static analysis result for SHA-256 f21d3f159cdbf4e7…

MALICIOUS

PDF

87.2 KB Created: 2021-07-14 08:00:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 9cb420fb998897fccf7f43eef688e8e3 SHA-1: 133fea91a26d7f29c152f3795ff7bae2e319a13d SHA-256: f21d3f159cdbf4e768fefb0037308909aac126e8ced9581baaa82bb19fbffb27
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many of which point to compromised WordPress sites and other disposable hosting. This structure is characteristic of a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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 http://28777886.com/Lpf/UPFILE/userfiles/files/94198395094.pdf In PDF document text
    • https://movesforfree.com/wp-content/plugins/super-forms/uploads/php/files/pldk1gffjmjbb2jl11ts758jh3/72525436765.pdfIn PDF document text
    • http://luingpyrex.cz/foto/Image/file/fikanilulirijakulugi.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/16089b34d80c81---jusovuxadatikubada.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/pia296l26c5qsufg21cdja6pf4/96678710220.pdfIn PDF document text
    • https://uppersanduskyrotary.com/cms/files/File/69214752778.pdfIn PDF document text
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606ca6d30d2d2---favifas.pdfIn PDF document text
    • http://jsdarvin.com/files/59033432677.pdfIn PDF document text
    • https://agsposure.org/wp-content/plugins/super-forms/uploads/php/files/21beebf60b6f19551c13c1e6034d1943/14647049328.pdfIn PDF document text
    • https://k-kompany.ru/wp-content/plugins/super-forms/uploads/php/files/40a529193a639afcca129d6d8895c02f/geradudozugudegi.pdfIn PDF document text
    • https://www.paparazzirestaurant.com.au/wp-content/plugins/super-forms/uploads/php/files/97288ab672eb43efd09dacafef682166/navoranilawozinuf.pdfIn PDF document text
    • http://audiomaster.se/wp-content/plugins/formcraft/file-upload/server/content/files/160979d3e35311---kiturojituzetizulazuboz.pdfIn PDF document text
    • http://duda-tech.pl/dudatech/upload/file/76789068301.pdfIn PDF document text
    • https://aduanaldelvalle.com/userfiles/file/dojodaxexuxetoji.pdfIn PDF document text
    • http://cariboohose.com/userfiles/file/nodeji.pdfIn PDF document text
    • https://edu-mate.kr/_UploadFile/Images/file/bufajeromud.pdfIn PDF document text
    • https://www.hintonassociates.com/wp-content/plugins/super-forms/uploads/php/files/778991144f5efcdf22676a6a6d05ae3c/19662189886.pdfIn PDF document text
    • https://www.eziblank.com/wp-content/plugins/super-forms/uploads/php/files/1f4a5032a27753f85e03ea453e07617c/jenerofera.pdfIn PDF document text
    • http://n2nlah.org/UserFiles/file/kixoxogurexevavizexapot.pdfIn PDF document text
    • http://omniatel.it/wp-content/plugins/formcraft/file-upload/server/content/files/160761443826d7---boximuzaxugugabim.pdfIn PDF document text
    • https://blueridgelightingandcontrols.com/wp-content/plugins/super-forms/uploads/php/files/08e3d972257c8b4af4447e48a2e3657b/76946945403.pdfIn PDF document text
    • https://loskutova.site/wp-content/plugins/super-forms/uploads/php/files/73cdc1ab391f82516cd4697e8b058d48/bejiketosufewolawutoze.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/ecpck4pmoc41cth7lct6o0mc2f/sujiruleved.pdfIn PDF document text
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072b6e62303a---vinugolamawekedelujedode.pdfIn PDF document text
    • http://cameralehiep.com/hinhanh_fckeditor/file/mujuko.pdfIn PDF document text
    • http://zjqzzx.com/uploadfile/file/2021070100575073499In PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=convert+image+to+high+quality+pdfPDF 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_off0000f12a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF12A 17548 bytes
SHA-256: 2e8b6f75ba76f0a9929ab2c196e48dec1b17b1bedd686eee0a5d982eba2b9869
font_01_sfnt_off00011d8f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D8F 11232 bytes
SHA-256: 85f7d61785ccffa6d6d456e0e4a65dd1d164e5b7fe93d465b06e8152f623866a
font_02_sfnt_off00013734.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13734 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1