Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1dc2e6627f25569…

MALICIOUS

PDF

81.0 KB Created: 2021-09-28 07:07:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 2f4bab23445ff462dd43985d1e74399c SHA-1: 4ccd9d7c81d7de8f05c6b8dd4317aaffdf4f4001 SHA-256: c1dc2e6627f25569131447ec6c128656bb8748cb0f968edba3f832b9bf467cb8
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs pointing to other PDF files hosted on a variety of domains, many of which appear to be disposable or low-reputation. The 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic indicates a deliberate attempt to create a link farm, a common tactic for distributing malicious content or conducting phishing. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9933

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 http://union.travel/ckfinder/userfiles/files/bafawoforosapodaroxifusi.pdf In PDF document text
    • http://gongin.humenia.com/upload/userfiles/2021/09/files/210925163105.pdfIn PDF document text
    • http://njuhome.pl/ckfinder/userfiles/files/losikigimewobazojo.pdfIn PDF document text
    • https://hoanghaie.com/Images_upload/files/pebosomojunowiximur.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/80umi5ipe26471mpq69qtbetc1/75754410926.pdfIn PDF document text
    • http://polimak.pl/userfiles/file/lagelumipabomudef.pdfIn PDF document text
    • https://zabulgaria.org/userfiles/file/67019018612.pdfIn PDF document text
    • https://tectrongim.com/uploads/files/livitowun.pdfIn PDF document text
    • http://liebherr-tr.com/userfiles/file/19513804940.pdfIn PDF document text
    • http://limobebe.com/userfiles/files/xewukexelujefujotekowas.pdfIn PDF document text
    • http://axi-hohenstein.de/userfiles/file/bubaluzulirevirarukofi.pdfIn PDF document text
    • http://thekitchendesignstudio.org/uploads/files/14893444339.pdfIn PDF document text
    • https://barrier.exma.cl/ckfinder/userfiles/files/10974463749.pdfIn PDF document text
    • https://kultmotor.hu/images/files/zewananibiwevikopubadeli.pdfIn PDF document text
    • http://curvesncontours.com/userfiles/file/sidalod.pdfIn PDF document text
    • http://marine-inox.com/i/File/poxozev.pdfIn PDF document text
    • https://nutstudio.it/userfiles/file/fatetiwulubiwunaj.pdfIn PDF document text
    • http://learningkey.org/userfiles/jorape.pdfIn PDF document text
    • http://sromedical.com/file_media/file_image/file/pimogipiwuxigatibu.pdfIn PDF document text
    • https://www.hotel-restaurant-plainfaing.fr/ckfinder/userfiles/files/werizo.pdfIn PDF document text
    • http://xn----7sbev0bhje.xn--p1ai/images/news/file/sutigowade.pdfIn PDF document text
    • https://beautydent.hu/editor_up/zimazaxuxegix.pdfIn PDF document text
    • http://kwiatmetal.pl/userfiles/file/majidadegelaperunukuw.pdfIn PDF document text
    • http://crystalnymph.by/wp-content/plugins/super-forms/uploads/php/files/454e868844471c9c65ed53fda1440ef3/jenusunapukasaketawopus.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=android+multi+tools+driver+64+bitPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b988.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB988 10780 bytes
SHA-256: b8b27b9205e70e884e24be3ada735b65b45163fa71fd2302c074fa1db7610ea7
font_01_sfnt_off0000d26b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD26B 18488 bytes
SHA-256: d55f15703742246ff0fa061bbea6cbfc9bb3f45871a0ba6cbb6c1e55e54111ec
font_02_sfnt_off00010273.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10273 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_03_sfnt_off00011a84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A84 17368 bytes
SHA-256: 5996f4afbea1b043ef4685a57dd0a9029f18c8ccc29f39c7d7ce8a0f797a42af