Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ded0ade6cbc562a…

MALICIOUS

PDF

75.1 KB Created: 2021-09-09 07:25:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a57d5870c1f8933609547d73b7c93c7b SHA-1: 99d2d913a0b358fe58277abd60ef08b802d1eee0 SHA-256: 8ded0ade6cbc562a833f0805577bf461d2c7e7478679825703403e1bc493b88a
166 Risk Score

Malware Insights

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

The sample is a PDF file identified as malicious by ClamAV and an ML classifier. It contains numerous external links, many pointing to other PDF files on various domains, suggesting it functions as a link farm. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for these links, which is common in phishing and malware distribution campaigns. No scripts were extracted, but the overall structure points to an attempt to lure users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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 http://schokozentrale.de/idata/kaboretelulavalumawakuz.pdf
    • https://theurbanthinktank.com/files/pepulawos.pdf
    • https://www.aicsmindia.org/ckfinder/userfiles/files/ludotukukujitowirup.pdf
    • http://veterinarioassociatopacinidallatorre.eu/userfiles/files/3879169319.pdf
    • http://vitali-schulz-eiskunstlaufen.de/userfiles/files/jegusisiselosewuvidem.pdf
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/16132d1d4e0ad4---rosis.pdf
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/irvhl1n4g333j32c4vgi7q97l4/63234695812.pdf
    • http://theartofdesign.nl/ckfinder/userfiles/files/vodas.pdf
    • http://daiichihr.com/uploads/news_file/nobovezidibudajona.pdf
    • http://futimisdev.com/userfiles/file/pevarapodifoza.pdf
    • https://tl-systems.hu/files/files/dojeno.pdf
    • http://klinok-saintp.ru/files/vebogepapur.pdf
    • http://phuvuongcorp.com/luutru/files/weripebufuwev.pdf
    • https://partroyfuneralhome.com/partroy/assets/file/pozatomedegozalawax.pdf
    • http://hani-bee.com/userfiles/files/semigeralesabolizor.pdf
    • http://presssimayeshahr.ir/pic/file/navesikejap.pdf
    • http://irvinenott.co.uk/ckfinder/userfiles/files/46307242135.pdf
    • https://frontivo.ro/userfiles/file/tapabizivejegapumaka.pdf
    • https://szemvidito.hu/sfwkr/feltoltesek/Images/Image/19471296827.pdf
    • http://np-laser.com/upload_fck/file/2021-9-2/20210902053050104697.pdf
    • https://vayamcs.com/content_files/files/7245465464.pdf
    • http://neilreardon.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/25772057879.pdf
    • https://warungmimpishio.com/contents/files/ruzinokuxasavivamefa.pdf
    • http://enidental.com/userfiles/file/20210907044656.pdf
    • http://cambresisemploi.fr/ckfinder/userfiles/files/90234707445.pdf
    • http://okfilm.kr/userData/board/file/25815045487.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=idle+miner+mod+apk+ios
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000bf53.bin
80b4111644b2e1c3192d16ce26596282b305a527410226ea9a80d4808bcb637f
pdf-font-stream PDF embedded font (sfnt) at offset 0xBF53 10496 bytes
font_01_sfnt_off0000d70e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD70E 16792 bytes
font_02_sfnt_off0000ef20.bin
8c5b9ea107162046df99bf306668d2d1c7673d1f9989db78416bbe57721b3bd9
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF20 18244 bytes