Malicious PDF — malware analysis report

Static analysis result for SHA-256 5527533bc663fba1…

MALICIOUS

PDF

83.9 KB Created: 2021-09-15 13:36:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: c7d5a17c15d5d2b60e61f6a772062696 SHA-1: fa73e363e522160dd2cd4079e5114524cb6995dc SHA-256: 5527533bc663fba170970e7f1dfc6504f604e129134020ca19f86b7520fd0806
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external URLs, suggesting it functions as a link farm or redirection mechanism to phishing or malware sites. The presence of embedded URLs and the heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://synerhu.ru/uplcv?utm_term=group+text+between+iphone+and+android PDF link annotation
    • http://agriturismocorteerbatici.it/userfiles/files/86949966769.pdfIn PDF document text
    • http://puntolinea.org/userfiles/files/bemamar.pdfIn PDF document text
    • http://studiotravenzolo.it/userfiles/files/22248673564.pdfIn PDF document text
    • http://www.gesas.it/media/mailinglist/file/magas.pdfIn PDF document text
    • https://jewfri.kr/files/image/files/84126356016.pdfIn PDF document text
    • http://sea-cruise.ru/ckfinder/userfiles/files/61970434558.pdfIn PDF document text
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613963f2b17bb---nodulokevezelot.pdfIn PDF document text
    • http://a1climbing.com/userfiles/files/tobixixilavikewoxegolopul.pdfIn PDF document text
    • http://telekommarketing.com/firme_data/files/59189557274.pdfIn PDF document text
    • http://anabakorea.jp/userfiles/file/somabixorig.pdfIn PDF document text
    • http://fusen-es.info/yamituki-n/uploads/files/suvepogeladukutaxix.pdfIn PDF document text
    • https://keralahappyjourney.com/ckfinder/userfiles/files/wuwavimaw.pdfIn PDF document text
    • https://yellowmangocafe.com/userfiles/file/bejufumeki.pdfIn PDF document text
    • http://creativetechno.in/userfiles/file/31838603.pdfIn PDF document text
    • http://cerritos.songhakbbq.com/uploads/files/vewilezino.pdfIn PDF document text
    • http://lnshiyue.com/userfiles/file/20210910090611_133853951.pdfIn PDF document text
    • https://congchungnguyenlieu.vnpec.xyz/uploads/files/65079139607.pdfIn PDF document text
    • https://maffart-guy.com/userfiles/file/66220703617.pdfIn PDF document text
    • https://artgallery.devctn.com/ckfinder/userfiles/files/jonijurejuxona.pdfIn PDF document text
    • https://www.lsv-wittlage.de/ckfinder/userfiles/files/75897244626.pdfIn PDF document text
    • http://ebd.su/UFD/7623/files/videj.pdfIn PDF document text
    • http://ingfrimale.com/userfiles/files/rametabirewisuj.pdfIn PDF document text
    • http://robfredo.com/userfiles/file/wefolovugexugafowurobe.pdfIn PDF document text
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/6e60bb61d78bbb139368278875bcc80b/85929706832.pdfIn PDF document text
    • http://kimura-shihoshoshi.com/userfiles/file/potodifegekuniriduselomi.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_off0000e2f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2F4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fb0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB0B 10740 bytes
SHA-256: f18d6ac2ac2b4d74df9781838f938348d85f9e29f4bfdbbf5078b60c64df5eb8
font_02_sfnt_off00011381.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11381 17880 bytes
SHA-256: 7b6327c270757c796fe09a029a8a3df1f7b9bae455f0bf249f36ecbb3983e72e