Malicious PDF — malware analysis report

Static analysis result for SHA-256 1121f631516d0a63…

MALICIOUS

PDF

85.7 KB Created: 2021-09-11 23:17:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-27
MD5: 1141eb381e54a6e37c1d1b83571e7684 SHA-1: 2ffecb3085889d61e8927510a86d310e60808935 SHA-256: 1121f631516d0a63e7851e9006fabeb2dd3b25085da500db94627599927cbc6a
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a large number of external URIs, many of which are hosted on disposable domains and appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or redirecting users to malicious content. The embedded JavaScript is a common technique for executing malicious code or initiating redirects within PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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 https://cructi.ru/uplcv?utm_term=best+business+game+android PDF link annotation
    • https://alley.52886.tw/uploads/files/47897886472.pdfIn PDF document text
    • http://hoteldazegliotorino.com/userfiles/files/25408486823.pdfIn PDF document text
    • http://eatoceanic.iorderfoods.com/uploads/files/65465740587.pdfIn PDF document text
    • http://sunriverps.com/data/editor/file/57778889886.pdfIn PDF document text
    • https://anne-berger.de/sites/anne-berger.de/files/fkcfile/folobegugafasomapesoxad.pdfIn PDF document text
    • http://hstairan.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/wadozijakug.pdfIn PDF document text
    • http://bluecreator.biz/ckfinder/userfiles/files/48362647529.pdfIn PDF document text
    • http://kdekdyjak.cz/data/6712524178.pdfIn PDF document text
    • https://beautydiction.com/ckfinder/userfiles/files/jepilajejerexewodarituke.pdfIn PDF document text
    • http://srtcivilnorth.com/ckeditor_file/files/liwozigumajodasafosizaso.pdfIn PDF document text
    • http://zhongjiukeji.com/upload_fck/file/2021-9-7/20210907221514433020.pdfIn PDF document text
    • http://africalegal.nl/userfiles/file/xonusewev.pdfIn PDF document text
    • https://fundacionamigosdelmarcaribe.ong/ckfinder/userfiles/files/32728662424.pdfIn PDF document text
    • http://nicolalazzarotto.com/userfiles/files/13429178754.pdfIn PDF document text
    • http://szakkepzosiklos.hu/upload/file/zelunefevutubur.pdfIn PDF document text
    • http://neoneofytou.com/ckfinder/userfiles/files/99373609193.pdfIn PDF document text
    • http://www.jacenter.org/js/ckfinder/userfiles/files/16805206572.pdfIn PDF document text
    • http://yenidenyuzlendirme.com/ckfinder/userfiles/files/94222145104.pdfIn PDF document text
    • http://duet-czluchow.pl/userfiles/file/15621904568.pdfIn PDF document text
    • https://ipic.vn/userfiles/file/gilomid.pdfIn PDF document text
    • https://knoxvilleremembers.com/media/5620133725.pdfIn PDF document text
    • http://orthodoxnews.us/file/43643965774.pdfIn PDF document text
    • https://www.grdr.org/paidel/ckfinder/userfiles/files/womijaxizavemitezosaz.pdfIn PDF document text
    • https://lapdonline.org/file/98078151679.pdfIn PDF document text
    • 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_off0000ece5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECE5 16796 bytes
SHA-256: 423ac1d5ebab01284346ca60c8edb2b4c6974c8e9006a419d6cc2a35b456051c
font_01_sfnt_off0001187e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1187E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013095.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13095 10840 bytes
SHA-256: 50747c32a043ee43d7c25fbfdb66a2b783bb8c3c8e86821faefed8cc7b681330