Malicious PDF — malware analysis report

Static analysis result for SHA-256 525053043e432802…

MALICIOUS

PDF

74.4 KB Created: 2021-09-17 00:10:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: fc5d0ef8afd5aff9ec59d7fbd35aa735 SHA-1: d7e42da4ad6752c6717bef5e6a57f78b8ed76af5 SHA-256: 525053043e4328024c40b37b28d9ac18b1a07f1058b98ecb3b886affd5115e13
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous external links, many pointing to compromised WordPress sites or disposable hosting, suggesting it functions as a link farm. The primary purpose appears to be directing users to potentially malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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://jancsoalapitvany.hu/ckfinder/userfiles/files/dupewodojevilarirewi.pdf In PDF document text
    • https://csn-alliance.com/data/files/favudaxonarapeguxe.pdfIn PDF document text
    • https://www.sesc-am.com.br/Selecao/ckfinder/files/42524323523.pdfIn PDF document text
    • https://glamweddingdesign.com/userfiles/file/14487386670.pdfIn PDF document text
    • http://kiiga.ru/userfiles/file/78153188597.pdfIn PDF document text
    • http://www.farmaciabergua.com/userfiles/files/foxibatureruzi.pdfIn PDF document text
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/ece6104d14fca29fb6905f3bdd840e89/19292672617.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142a63254553---66916400125.pdfIn PDF document text
    • http://www.specemc.ru/upload/files/dukimasisu.pdfIn PDF document text
    • http://pes.edu.mn/ckfinder/userfiles/files/44602693667.pdfIn PDF document text
    • https://nayyaralidada.net/alpha/ckfinder/userfiles/files/gilosinokigidizuzegeseja.pdfIn PDF document text
    • http://nickelsgrafikdesign.de/ckfinder/userfiles/files/wewigefivup.pdfIn PDF document text
    • http://etyekilovarda.hu/userfiles/file/38618900512.pdfIn PDF document text
    • https://pleasanton.com/wysiwygfiles/file/40126504880.pdfIn PDF document text
    • http://mmbc.cz/_data/user_files/file/babonagajorodo.pdfIn PDF document text
    • https://datatech-int.com/userfiles/file/gokalef.pdfIn PDF document text
    • http://sipzip.com/userfiles/file/14651870259.pdfIn PDF document text
    • http://elard-group.com/ckfinder/userfiles/files/xifobi.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613a86d7463dc---kuruxof.pdfIn PDF document text
    • http://hoya-system.com/uploads/files/202109042001148342.pdfIn PDF document text
    • https://pensionradvanice.cz/res/file/33927748052.pdfIn PDF document text
    • http://konemara.hu/userfiles/file/mepetijes.pdfIn PDF document text
    • http://ekorepetycje.eu/Upload/file/kifim.pdfIn PDF document text
    • http://www.psoevalledeabdalajis.es/ckfinder/userfiles/files/6503322234.pdfIn PDF document text
    • https://classoft.ro/userfiles/file/45904258627.pdfIn PDF document text
    • http://kavernoklub.com/campannas/file/37783845751.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=gta+san+andreas+mod+apk+happymodPDF 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_off0000be5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE5D 17152 bytes
SHA-256: 36332e0a6d264dc673dbd80b3d739f4fbc3378a1201862e0fc2c43690be96285
font_01_sfnt_off0000eaf8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAF8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001030f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1030F 10764 bytes
SHA-256: 3812940828acfccb3b716e1adfba6baca695efc267ca1d015de1aa8c927d43dc