Malicious PDF — malware analysis report

Static analysis result for SHA-256 82b5faf06cb06be8…

MALICIOUS

PDF

99.2 KB Created: 2021-09-08 16:59:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 8cff9714f755540a2b807ecbc4cbc9a8 SHA-1: 048009df29548803a1c0da51e61e87d38ac4e95f SHA-256: 82b5faf06cb06be80d7201a93112fccad5c2c65925fc2b76ab1782e046235615
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, embedding numerous URLs that point to compromised WordPress upload directories and disposable hosting. These links likely serve as lures for phishing or to distribute further malware, aligning with the characteristics of a malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9961

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://infrive.ru/uplcv?utm_term=professional+ethics+pdf+download PDF link annotation
    • https://bbensonmft.com/wp-content/plugins/super-forms/uploads/php/files/1452b6a2dfe2931d3fbac95c1720a358/69211976275.pdfIn PDF document text
    • http://kraski-chernila.ru/resources/file/jomaxurozisojilawotibuz.pdfIn PDF document text
    • http://manvilastrust-org.bvirani.com/ckfinder/userfiles/files/luzovozetizupasepofujazul.pdfIn PDF document text
    • http://dainichiji.com/upload_ckr/files/33909963727.pdfIn PDF document text
    • http://trenermichal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/161300664e7d6c---9379787831.pdfIn PDF document text
    • https://xo-sound.ru/userfiles/file/ravugowejinovixewuwedoxeg.pdfIn PDF document text
    • http://pointerboards.com/uploads/admin/files/fububilalus.pdfIn PDF document text
    • http://anninh247.info/upload/files/15276031223.pdfIn PDF document text
    • https://victory-agency.com/wp-content/plugins/formcraft/file-upload/server/content/files/161387ac30a833---89957045216.pdfIn PDF document text
    • http://dyglas.com/userData/board/file/29961185728.pdfIn PDF document text
    • http://embeddedhr.com/ckfinder/userfiles/files/tafaxogekew.pdfIn PDF document text
    • https://orig-shop-gsm.ro/ckfinder/userfiles/files/35950397880.pdfIn PDF document text
    • http://juditphotography.com/picture/userfiles/file/tugerajaketamara.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/3klg2dpl60cqgl08a42rrf88en/13605019612.pdfIn PDF document text
    • http://caratow.eu/userfiles/file/diwomimovorop.pdfIn PDF document text
    • http://gmei.lt/ckfinder/userfiles/files/88829952532.pdfIn PDF document text
    • http://k1a.ru/images/files/file/fumusejafufatod.pdfIn PDF document text
    • http://sns.hu/_user/file/tubakozoxarolixawob.pdfIn PDF document text
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161354bff0607e---87961544319.pdfIn PDF document text
    • http://boston.pl/fck_pliki/file/rurobelij.pdfIn PDF document text
    • http://tiszaladany.hu/upload/file/bujepiv.pdfIn PDF document text
    • https://crownprolaw.com/userfiles/Proj_Name/files/venafolur.pdfIn PDF document text
    • http://kleinschadenexpert.de/userfiles/file/gufekerexupawotigize.pdfIn PDF document text
    • https://agroadvanced.com/app/webroot/newsletters/editor/files/vurukexijoman.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_off00011ca4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CA4 10804 bytes
SHA-256: a3e2c9c941b003a840263629d48fc6b1316a8133a532ff47b3d2388fb46fbc1a
font_01_sfnt_off0001358d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1358D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014d9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14D9F 18768 bytes
SHA-256: e38ebf34784bc935ca9b9cc883e5913d03e74d7393be1bfe00ad3199e9c5127b