Malicious PDF — malware analysis report

Static analysis result for SHA-256 9813c4e7ae93325a…

MALICIOUS

PDF

88.4 KB Created: 2021-09-12 22:49:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: a966cbdd5f917d2ee56e65c7b08d2e5c SHA-1: 09463b44da5d393842578df51a15cf5b452a19ab SHA-256: 9813c4e7ae93325a7e776fb708f1b36c92a9e3aae6b1aa917501717e28914c6c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to numerous external URLs hosted on potentially compromised or disposable domains. While no scripts were explicitly extracted, the PDF format often leverages embedded JavaScript for malicious actions, such as redirecting users to phishing sites or initiating further downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://fc-junajted.com/upload/datoteke/15019248167.pdf In PDF document text
    • http://amadpich.com/userfiles/file/golaxe.pdfIn PDF document text
    • http://codienlanhtrangia.com/Images_upload/files/jafawilamopodenewemokuja.pdfIn PDF document text
    • https://reazfarah.com/ckfinder/userfiles/files/wigadilanofaw.pdfIn PDF document text
    • https://radekslodkiewicz.pl/files/file/91323770018.pdfIn PDF document text
    • https://lenaoyunlar.com/calisma2/files/uploads/pozowo.pdfIn PDF document text
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136c5407e417---pawizo.pdfIn PDF document text
    • http://global-gypsum.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e42e06521e---5797852460.pdfIn PDF document text
    • https://www.superioreagle.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e0495be625---17423391963.pdfIn PDF document text
    • http://librojuridico.com/aym_images/files/13833921093.pdfIn PDF document text
    • http://aqcorth.specialty-match.com/upload/files/xekigexiruw.pdfIn PDF document text
    • https://clearpatth.com/userfiles/file/40084197296.pdfIn PDF document text
    • http://nanopena.cz/upload/file/33968294474.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161394aad59674---weletoweg.pdfIn PDF document text
    • http://infinity-c-t.com/userfiles/file/60413978223.pdfIn PDF document text
    • http://alpes-de-haute-provence.proximeo.com/ckfinder/userfiles/files/xuzisas.pdfIn PDF document text
    • https://pollackmihalyiskola.hu/ckfinder/userfiles/files/58227853804.pdfIn PDF document text
    • http://c2ctrading.org/cms_upload/files/28888678393.pdfIn PDF document text
    • http://tensoinox.com/userfiles/files/99431910905.pdfIn PDF document text
    • http://salondebellezaanamariaromero.es/ckfinder/userfiles/files/7040578564.pdfIn PDF document text
    • http://lafenicealcamo.it/userfiles/files/5848666553.pdfIn PDF document text
    • http://e2ingenieros.com/ckfinder/userfiles/files/firaxuvusujijegiwirugaxuj.pdfIn PDF document text
    • http://hyundai-dongdo.vn/images/files/18834687308.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/161393d6a892b6---76527471611.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=my+tv+cast+mod+apkPDF 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_off0000f41c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF41C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010c2e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C2E 18288 bytes
SHA-256: a4d9d893ae1cbffa82fe01897d1a73303f4b7ea84543f2dcc36942762fd1cbd0
font_02_sfnt_off00013c05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13C05 10468 bytes
SHA-256: e1a18f0305911ee738f66cb1b0f3701c2b7cbeca766f37928834cdfef74a83e1