Malicious PDF — malware analysis report

Static analysis result for SHA-256 f5e3b62ac98a1a22…

MALICIOUS

PDF

84.5 KB Created: 2021-07-31 12:42:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 243928c655a6914e77a0c514a64f8db3 SHA-1: d79b56fc7987d8b280ec11c82b3824fa9dfa1f85 SHA-256: f5e3b62ac98a1a221f33918e0427a7870b340015b3839bd095ddcfb56e882bbd
156 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 compromised CMS upload directories or are part of a link farm hosted on disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically phishing or malware distribution. The document body is heavily obfuscated and unreadable, providing no direct textual clues, but the heuristic findings are sufficient to infer the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

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://www.valathors.com/ckfinder/userfiles/files/golibazevevepofekixajasa.pdf In PDF document text
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/16089cfb360358---57199580.pdfIn PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b4d3a1d31b---33201133637.pdfIn PDF document text
    • https://seitonsolutions.com/ci/files/37590992657.pdfIn PDF document text
    • http://technocom.pl/editor/file/86541084314.pdfIn PDF document text
    • https://robotics-institute.com/wp-content/plugins/super-forms/uploads/php/files/6hsaboamuc2gs9ef9ti1nn3597/balofudaf.pdfIn PDF document text
    • http://hocikto.info/userfiles/file/6720069748.pdfIn PDF document text
    • http://hi-reid-solutions.com/wp-content/plugins/super-forms/uploads/php/files/2030bf12be228f0b494531e8e9f13c65/84621262701.pdfIn PDF document text
    • http://przychodnia-felinskiego.pl/uploads/editor/file/101188411.pdfIn PDF document text
    • https://nicosiacaffe.it/file/79112052397.pdfIn PDF document text
    • https://ngoctraithaibinhduong.com/uploads/news_file/8761650411.pdfIn PDF document text
    • http://opusincertum.it/userfiles/files/23242666454.pdfIn PDF document text
    • http://www.gcsystem.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160fe5df481896---32574525931.pdfIn PDF document text
    • http://www.suffaheducation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609672a039149---63016010167.pdfIn PDF document text
    • http://hms31.ru/img/file/josenuvefozonivavemuba.pdfIn PDF document text
    • http://simkoongschool.com/uploads/editer/files/92417611102.pdfIn PDF document text
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c74933fe7a---nesimupadubata.pdfIn PDF document text
    • http://barsugo.com/ckfinder/userfiles/files/29421938138.pdfIn PDF document text
    • https://altonika.pro/files/fck/file/94424377791.pdfIn PDF document text
    • http://aftckwt.com/uploads/file/luxibaxizimogu.pdfIn PDF document text
    • http://www.asslar.de/downloads/padefizexolofezupejefig.pdfIn PDF document text
    • http://ubest.ru/images/file/witefesojuzuxoru.pdfIn PDF document text
    • http://jfhconsultancy.nl/userfiles/files/70853095165.pdfIn PDF document text
    • http://dailitara.lt/bites/uploads/file/11933363494.pdfIn PDF document text
    • https://motacademy.it/file/70454007686.pdfIn PDF document text
    • https://groupburuemas2.com/contents//files/gozonubakopinef.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=are+cast+iron+toys+worth+anythingPDF 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_off0000e1c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1C5 18376 bytes
SHA-256: d55c5c764eb8da64a4c6f546a3ec56789eeb0d30eff607c68080b9477e64539e
font_01_sfnt_off00011190.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11190 10644 bytes
SHA-256: 6d619d5702f08f6e0fa47b86c6903baa2bba5a276d5c210fc7c350714b933b3b
font_02_sfnt_off00012a04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A04 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1