Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf9987275b0be5b1…

MALICIOUS

PDF

69.8 KB Created: 2021-09-25 19:44:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 04cee5ef46f33afd13328498c5db3b84 SHA-1: 75e90729cd1b92be4d365732e391994b747279dc SHA-256: cf9987275b0be5b1b8bbaad01a50b504457fc38147db19741160f7c997b77399
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file is identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous URLs pointing to potentially compromised websites or disposable hosting, often using 'utm_term' parameters suggestive of phishing lures. The PDF structure and embedded URIs strongly suggest an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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=real+robux+generator+no+human+verification PDF link annotation
    • http://usefchina.com/uploadfile/file///2021091804474977.pdfIn PDF document text
    • http://wedding-box100.com/uploads/files/202109220849338508.pdfIn PDF document text
    • http://krallarintavugu.com/upload/file/zeturajoniwolatozenunali.pdfIn PDF document text
    • http://stainless-faucet.com/uploads/htmlupload/files/97345143007.pdfIn PDF document text
    • https://oldgradeducation.com/ckfinder/userfiles/files/63749692110.pdfIn PDF document text
    • http://zhongjiukeji.com/upload_fck/file/2021-9-20/20210920120146157597.pdfIn PDF document text
    • http://old.bgk-meshkova.com/ckeditor/ckfinder/userfiles/files/gobetodep.pdfIn PDF document text
    • http://easyliveconstruction.com/ci/userfiles/files/78104187940.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1613d7801f2fa1---61615621904.pdfIn PDF document text
    • http://dailyliving.nl/ckfinder/userfiles/files/40766781011.pdfIn PDF document text
    • http://autosoftware.company/autoresponders_images/files/54438016508.pdfIn PDF document text
    • https://bgg.pirkitpadangas.lt/ckfinder/userfiles/files/dakujolujalomidofiribe.pdfIn PDF document text
    • http://www.sname.org.tw/sname/ckfinder/userfiles/files/fupuzadalelode.pdfIn PDF document text
    • http://ttfi.org/app/webroot/userfiles/file/diluveworenikakotaritid.pdfIn PDF document text
    • http://fleshlight-tw.com/userfiles/file/36040089592.pdfIn PDF document text
    • https://gtsonline.nl/wp-content/plugins/super-forms/uploads/php/files/fv6iiohjvjivrce41vkejlcr52/55382154184.pdfIn PDF document text
    • http://chapaconoticias.com/assets/ckfinder/core/connector/php/uploads/files/dajiwilafebunivegata.pdfIn PDF document text
    • https://groupits.cm/uploads/fck/file/93673850288.pdfIn PDF document text
    • https://kotata-zlin.cz/obr/clanky/file/sesubeduwifijedalamal.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/16143dddfa4140---bafeb.pdfIn PDF document text
    • https://gozdekadife.com/resimler/files/tafiban.pdfIn PDF document text
    • https://rdw-wolf.de/backend/ckfinder/userfiles/files/rugirifoxovibijelodafi.pdfIn PDF document text
    • https://www.mftelhas.com.br/adm/Editor/ckfinder/userfiles/files/vavolel.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_off0000b26d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB26D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ca84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA84 11068 bytes
SHA-256: a742f39046b130863c5fc316e5cfb2fbd814e492bbe2541595ec8679bc614557
font_02_sfnt_off0000e41f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE41F 14760 bytes
SHA-256: de24d0a373aac9ae83cdc75866b281f7e3a02c184f02c1ffdb1189e7b16c40b4