Malicious PDF — malware analysis report

Static analysis result for SHA-256 236a3dddf9ede924…

MALICIOUS

PDF

73.6 KB Created: 2021-09-11 00:53:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 3cfe7c883f3018840decb5eec8ac14ae SHA-1: 6a33c65e9538e0cdfdc974bfa0db0eea5b9ad24d SHA-256: 236a3dddf9ede924625bf9d97418f9a2e0512af37937a95115b0db852731c56d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to link farms on disposable hosting, indicating a phishing or malware distribution attempt. The ClamAV detection and ML classifier strongly suggest malicious intent. The document body is heavily obfuscated, but the presence of multiple external links and the overall structure point towards a lure to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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 https://infrive.ru/uplcv?utm_term=robo+defense+free+full+version PDF link annotation
    • http://24hnbc.com/assets/ckfinder/core/connector/php/uploads/files/75837027605.pdfIn PDF document text
    • http://makinsushi.com/uploads/files/46184780825.pdfIn PDF document text
    • https://wotfiles.com/ckfinder/userfiles/files/sakarejisibevisiforuxag.pdfIn PDF document text
    • https://myvideoclasses.com/ci/userfiles/files/xadifut.pdfIn PDF document text
    • https://mk-promotions.com/ckfinder/userfiles/files/13838124415.pdfIn PDF document text
    • https://barrierball.cl/ckfinder/userfiles/files/44129586973.pdfIn PDF document text
    • https://orsam.org.tr/paketler/ckfinder/dosyalar/files/70124427118.pdfIn PDF document text
    • http://www.farparts.cl/wp-content/plugins/formcraft/file-upload/server/content/files/16133f38dd5729---xutidoz.pdfIn PDF document text
    • https://clinicamanila.com/ckfinder/userfiles/files/24200457565.pdfIn PDF document text
    • http://duet-czluchow.pl/userfiles/file/jutupufakolowosonawajufej.pdfIn PDF document text
    • https://spyboarcams.com/files/26954067657.pdfIn PDF document text
    • http://werkkledingverkoop.nl/images/docman/files/soziluwarenavotivimelof.pdfIn PDF document text
    • http://travelci.ru/ckfinder/userfiles/files/73461628161.pdfIn PDF document text
    • https://optimuselearningschool.aels.edu/learning/site/images/uploadfiles/jupopedofubav.pdfIn PDF document text
    • https://topinsolventa.ro/userfiles/file/50969715244.pdfIn PDF document text
    • https://s-h.cc/uploads/files/202109100054036092.pdfIn PDF document text
    • https://sukienmiennam.com/userupload/files/13800485196.pdfIn PDF document text
    • http://tiwtactic.com/userfiles/files/vatunogaw.pdfIn PDF document text
    • http://rigassprotes.lv/uploadz/file/kuwutajudejij.pdfIn PDF document text
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/53e4ceaaaca0b4cb3507ee90c217f7d2/fomoxadurogivo.pdfIn PDF document text
    • https://ckmandarin.com/uploads/zididuzij.pdfIn PDF document text
    • http://winfielddeli.com/ckfinder/userfiles/files/mobesomirisevuxarizudi.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_off0000bc88.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC88 17204 bytes
SHA-256: c65c60bd2224b729cb6acb3896a609289b4cae46df7d441ab21c25bcf6803e35
font_01_sfnt_off0000e929.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE929 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010140.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10140 10436 bytes
SHA-256: 21b2cfab64cec271cc2c3ef57dac1cb20ae13fb0658966cdd11869ca43d46996