Malicious PDF — malware analysis report

Static analysis result for SHA-256 99b19ac9cbbd47e1…

MALICIOUS

PDF

81.8 KB Created: 2021-09-09 17:04:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: c5f325e9507f41f1964ca82104935c0c SHA-1: 7cd58bd4455804bf468cfbc7f86b61243fe45b24 SHA-256: 99b19ac9cbbd47e13f9ea916ccd3d5be8e39fb04072d963843442f2ca0675af7
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs pointing to disposable domains, indicative of a link farm designed to distribute malicious content or facilitate phishing. While no scripts were explicitly extracted, the PDF structure and heuristic firings strongly suggest an intent to lure users to external, untrusted resources.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

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://tfh-filter.hu/_user/file/11441704263.pdf In PDF document text
    • https://viessmannboilers.ca/fck_upload/file/rolajadoroli.pdfIn PDF document text
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/161304bc375e5c---14029739246.pdfIn PDF document text
    • http://rrarental.org/upload/file/moferunojegemivusosimom.pdfIn PDF document text
    • http://kanomax-nsk.ru/images/gimufo.pdfIn PDF document text
    • https://vivekanandbawwa.com/userfiles/file/5736610582.pdfIn PDF document text
    • http://raegcafe.com/uploads/files/kapadufoxujiwajuru.pdfIn PDF document text
    • http://esistore.de/userfiles/file/xinazasigejawikupokito.pdfIn PDF document text
    • http://austria-ex.com/images/blog/file/mimazojezafonubasiwebulo.pdfIn PDF document text
    • http://www.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/e24o9u7p7h6kj1n7hlv65sfqc2/dunadarofikesulonopipov.pdfIn PDF document text
    • http://burragebrothers.org/demo/jolie/beta/userfiles/files/23667520656.pdfIn PDF document text
    • https://nomortiga.com/contents/files/40947217013.pdfIn PDF document text
    • https://nevjegyzek.eu/uploads/file/galurupegoxitusesawidaje.pdfIn PDF document text
    • http://mmprogetti.it/userfiles/files/vetawiroxelukizogexur.pdfIn PDF document text
    • http://www.valathors.com/ckfinder/userfiles/files/25005976428.pdfIn PDF document text
    • http://marthomaiticherukole.com/userfiles/file/pugukikubuxadupifoz.pdfIn PDF document text
    • http://studiomontironi.eu/userfiles/files/katevufuguf.pdfIn PDF document text
    • https://webaprint.be/img/file/lazaxomodulagekaradore.pdfIn PDF document text
    • https://tch.lu/files/files/wufejabuleketevak.pdfIn PDF document text
    • http://progfin.pl/userfiles/file/joxekazo.pdfIn PDF document text
    • http://orthopaede4you.de/userfiles/file/golufawudixopizemufidafa.pdfIn PDF document text
    • https://nffcd.org/userfiles/files/1059037493.pdfIn PDF document text
    • http://rem-proekt.com/f/file/wimuxorutugizoreba.pdfIn PDF document text
    • http://sgo-bage.com/public/files/files/vawizotofuvekisoxiji.pdfIn PDF document text
    • http://aexpress.lv/index/images/up/file/nopobunujaxolonebudevet.pdfIn PDF document text
    • http://mispuntossaga.com/campannas/file/8491391406.pdfIn PDF document text
    • http://xn--80aa5alfu.kz/file/12530145375.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=convert+pdf+to+indesign+2020+freePDF 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_off0000dd43.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD43 10804 bytes
SHA-256: 0d62af845aabdc72edff5a81b11e718c392ae9c7577adc852b5a3643d21e312b
font_01_sfnt_off0000f625.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF625 16588 bytes
SHA-256: 92ad0c2242ea8a56a137fd07c1800efd9639ec6e23d54fb64925342c48dda711
font_02_sfnt_off0001211f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1211F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1