Malicious PDF — malware analysis report

Static analysis result for SHA-256 91b7963032423975…

MALICIOUS

PDF

85.9 KB Created: 2021-09-14 01:37:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: de82459136f3b8a121bb368743b104e1 SHA-1: 2842b5f783be90e84b4965ae3f129124db8b7aa9 SHA-256: 91b79630324239750ec4af9a96dd236fc12d66bdab06afb3ba7225a8ac346cac
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple compromised websites and disposable hosting domains. The embedded URLs and the nature of the heuristics strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://infrive.ru/uplcv?utm_term=android+app+patterns PDF link annotation
    • https://ristovski.mk/public_html/upload/userfiles/file/vujojulunikugo.pdfIn PDF document text
    • http://odpadykj.cz/UserFiles/File/24415583557.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/161319a0f71874---depazizo.pdfIn PDF document text
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613db4169f477---wofibuzefukajogugub.pdfIn PDF document text
    • http://itfkarnataka.com/cvsprojects/SSK/Source/2.0.0/images/files/31376232238.pdfIn PDF document text
    • http://pzhjintai.com/upload/files/xovasoxoxorubuxuj.pdfIn PDF document text
    • http://design-klasse.de/ckfinder/userfiles/files/48176741286.pdfIn PDF document text
    • https://mallorcaboom.com/res/wysiwyg/file/vurapazigalafananax.pdfIn PDF document text
    • http://0vote.com/ckfinder/files/9453265386.pdfIn PDF document text
    • http://xn----7sbab1bcaqplb0ccyi9d.xn--p1ai/files/file/22408689593.pdfIn PDF document text
    • http://hennel.hu/sources/elemek/file/bitanupomasuwoxidimuvusif.pdfIn PDF document text
    • http://immodraft.nrw/images/architekten_agentur_images_/file/fujoweromozatuvajapej.pdfIn PDF document text
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/85b3f3b9cb0f97623c3082f08b90daa1/78247737702.pdfIn PDF document text
    • https://digicpictures.com/downloads/1982540847.pdfIn PDF document text
    • http://simkoongschool.com/uploads/editer/files/nalelutegovufebegepozoram.pdfIn PDF document text
    • http://vngo-cc.vn/cooker/public/files/welekemob.pdfIn PDF document text
    • http://hoinhikhoavn.com/img/files/92581262246.pdfIn PDF document text
    • https://asiantms.com/ckfinder/userfiles/files/38355886213.pdfIn PDF document text
    • http://counterreaction.net/wp-content/plugins/formcraft/file-upload/server/content/files/161339254332ee---tokirilubo.pdfIn PDF document text
    • https://ourcampuswindow.com/ckfinder/userfiles/files/51198453384.pdfIn PDF document text
    • http://jan-fotografie.nl/upload/files/dasatug.pdfIn PDF document text
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/tabegiferul.pdfIn PDF document text
    • http://posuni.com/userfiles/file/lewadolu.pdfIn PDF document text
    • http://gildiamasterov.ru/userfiles/file/47063320946.pdfIn PDF document text
    • http://longarmquiltacademy.net/fckeditor/userfiles/file/mapejilinab.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_off0000eb91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB91 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000103a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103A8 10320 bytes
SHA-256: 22e5e0fc067feb28aa4cf618e2a656f33b4c8bf9219edbed5154f96bd4c7fa6e
font_02_sfnt_off00011b08.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B08 18056 bytes
SHA-256: c5c67e91417cd132056f951566ba9b277cdeb4980e27e6c59473040b94c95b35