Malicious PDF — malware analysis report

Static analysis result for SHA-256 2aa95b2a456ebc98…

MALICIOUS

PDF

95.9 KB Created: 2021-09-16 12:19:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 5ce6abb0ce52342517b9cf658796bd82 SHA-1: ac8636f05d19b1a3089595265db7e7731c642233 SHA-256: 2aa95b2a456ebc98902e7330c81dee1a7c7a17bf23ed686be8ec9b243c3e92d7
126 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ML classifiers and ClamAV as malicious. It contains numerous external URIs, many of which point to potentially malicious domains, and one heuristic specifically identifies it as a link farm on disposable hosting. The ML classifier output of 0.996 suggests a high likelihood of malicious intent, likely related to phishing or redirecting users to exploit kits.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://punaide.com/userfiles/files/jiwiwez.pdf In PDF document text
    • http://ombs.ru/uploads/files/sazuzid.pdfIn PDF document text
    • https://europacreativaeuskadi.eu/files/galeria/files/39104921097.pdfIn PDF document text
    • http://087334211.kad.tw/kads/ckfinder/userfiles/files/wokekinepubot.pdfIn PDF document text
    • https://radekslodkiewicz.pl/files/file/xofixerirazarika.pdfIn PDF document text
    • http://issaproject.com/app/views/panel/ckfinder/userfiles/files/ronexugebirifukidimox.pdfIn PDF document text
    • http://cs-golfclub.com/ckupload/files/tazezumuzatopusi.pdfIn PDF document text
    • http://digilit.ir/basefile/digilitir/files/vifovolunukadolexata.pdfIn PDF document text
    • https://fiberglasssupplydepot.com/userfiles/files/vobufulazebuzu.pdfIn PDF document text
    • https://www.frontierexim.com/wp-content/plugins/super-forms/uploads/php/files/709irkpv2qh9m0u64spfc0jpf6/ranelutuzag.pdfIn PDF document text
    • https://www.baptistenhardenberg.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613f25a6c0ea7---31420926174.pdfIn PDF document text
    • http://hyundaidongdo3s.com/images/files/17263581371.pdfIn PDF document text
    • http://beautybybelief.com/admin/images/file/60002382965.pdfIn PDF document text
    • http://lnv-cnc.gr/userfiles/file/47202780962.pdfIn PDF document text
    • http://ekachaiguitarist.com/ckfinder/userfiles/files/mamisopetewubopaxibiwa.pdfIn PDF document text
    • http://dijladentalcenter-qa.com/userfiles/file/39946357204.pdfIn PDF document text
    • http://corse.annuaire-regional.com/ckfinder/userfiles/files/23816532814.pdfIn PDF document text
    • http://ansatrans.ru/admin/ckfinder/userfiles/files/78086688977.pdfIn PDF document text
    • http://www.ambatownship.com/ckfinder/userfiles/files/21864851396.pdfIn PDF document text
    • http://s-pack.kr/userfiles/file/20210916065347.pdfIn PDF document text
    • http://shengnabei.com/uploadfile/file///2021091221234931.pdfIn PDF document text
    • http://gbfrjournal.org/pds/userfiles/files/xusonubuza.pdfIn PDF document text
    • http://esenkardeslerinsaat.com/resimlerfiles/dofazezisiw.pdfIn PDF document text
    • http://tvkinter.com/file_media/file_image/file/35744159716.pdfIn PDF document text
    • https://rgcsmt.org/ckfinder/userfiles/files/23329542885.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=c%2B%2B+in+21+days+pdfPDF 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_off000114fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114FA 17636 bytes
SHA-256: b941f7df9a9879fd6bd6e42feccff9a8f9bf03aa473f59a746f4c80adef63d6d
font_01_sfnt_off0001425b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1425B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015a72.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15A72 10312 bytes
SHA-256: 80e5baf2e17aa9aeaf390d9dad059aa159c24f5b3d4815c4c126e1fbc7c8a7d3