Malicious PDF — malware analysis report

Static analysis result for SHA-256 971a870b31dc34a7…

MALICIOUS

PDF

80.5 KB Created: 2021-09-18 13:20:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 2c89dc50eca080104226c80e07f56559 SHA-1: 28bc648f9df9d980bd2aa0f649f7476f56ac2fd8 SHA-256: 971a870b31dc34a711d84bfe0081487a0aa8454aab664025a83eece57ef81b23
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised WordPress sites. The presence of numerous links on disposable hosting and the use of UTM parameters suggest an attempt to obscure the true malicious destination and potentially distribute malware or conduct phishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://oniceh.ru/uplcv?utm_term=gta+san+andreas+mobile+phone+mod PDF link annotation
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161330cad826b2---lilaliserezimegoli.pdfIn PDF document text
    • https://fairtradeportal.pl/userfiles/file/41132100936.pdfIn PDF document text
    • http://jiuxingchaoshi.com/uploads/file/161600366735.pdfIn PDF document text
    • http://baraanduliaptti.org/userfiles/file/dexopej.pdfIn PDF document text
    • https://rjpexport.com/files/1540283348.pdfIn PDF document text
    • http://pronobile.de/catalog/file/21098925855.pdfIn PDF document text
    • http://szymonadamczyk.pl/uploads/fck/file/nodemefomenaxizor.pdfIn PDF document text
    • http://szwygs.com/upload/90416584012.pdfIn PDF document text
    • http://kanalizace-ul.cz/userfiles/file/83999673716.pdfIn PDF document text
    • https://www.cylinder96.ru/admin/ckfinder/userfiles/files/nidiwokerowolewurit.pdfIn PDF document text
    • https://fototipia.hu/files/files/nufamuwowebugexusus.pdfIn PDF document text
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1613cad8677555---37893391987.pdfIn PDF document text
    • http://refpecsbelvaros.hu/kepek/files/jufaw.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f3b9276192---kakata.pdfIn PDF document text
    • http://oguzlarotomatiksanziman.com/depo/sayfaresim/file/bumenuna.pdfIn PDF document text
    • http://nsdadventist.org/FCKData/file/fixenarizotubuxujogep.pdfIn PDF document text
    • http://allamericannursing.com/userfiles/file/65086415187.pdfIn PDF document text
    • http://indianspringhomes.net/userfiles/files/xofiw.pdfIn PDF document text
    • http://kagoshimakojintaxi.com/userfiles/file/rarowizuduradazed.pdfIn PDF document text
    • http://lev-steklo.ru/userfiles/file/pukuked.pdfIn PDF document text
    • http://livelyway.com/ckfinder/userfiles/files/tatutun.pdfIn PDF document text
    • http://theclelandgroup.com/img/upload/file/kixezi.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_off0000d425.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD425 10836 bytes
SHA-256: 14f1e153c34b2d4bb24658faa3a7939001bde8b45cf79c53a7a678603b300692
font_01_sfnt_off0000ecb4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECB4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000104c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104C6 18740 bytes
SHA-256: a0daa18ab7ad3235b4b4cc010a7c95ef1cebf680f1462ea8b50de5b091a8ee57