Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f189369b4a7af6e…

MALICIOUS

PDF

79.2 KB Created: 2021-09-21 12:08:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 6006602a0ba9ae21c5bde686caa0eb6b SHA-1: f3fa681fe3421152e87c52630f2bbad874d99460 SHA-256: 3f189369b4a7af6ed3ffdbe068c393164295ccf99e03e630aa577b9875422cb6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The file contains numerous embedded URLs, many pointing to compromised CMS upload directories, suggesting it functions as a link farm to distribute further malicious content or phish users. The presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

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 https://philabc.ru/uplcv?utm_term=free+robux+games+real PDF link annotation
    • https://brylka-kfz.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613b24027f47f---6005600033.pdfIn PDF document text
    • https://mithermomix.com.mx/wp-content/plugins/super-forms/uploads/php/files/4ee1484090480f6c4bd2001cb69e7e8e/zalofarozuzokokap.pdfIn PDF document text
    • https://es21sys.com/userfiles/file/72223126154.pdfIn PDF document text
    • http://noithatsah.com/webroot/img/files/8921146615.pdfIn PDF document text
    • http://bndweb.nl/upload/files/78612783061.pdfIn PDF document text
    • http://aqcorth.specialty-match.com/upload/files/18659726960.pdfIn PDF document text
    • https://emailing-online.fr/uploads/userfiles/file/gidovebisaxux.pdfIn PDF document text
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1613f2ec01077d---58129373186.pdfIn PDF document text
    • https://www.tcf.gov.tr/ckfinder/userfiles/files/78160809180.pdfIn PDF document text
    • http://nova-auto.com/upload/482750840.pdfIn PDF document text
    • http://laptopcuhaiphong.vn/upload/files/zejoju.pdfIn PDF document text
    • http://af.ssla.ru/images/fornews/files/kerijisajuvowuf.pdfIn PDF document text
    • http://ahkjt.com/upfile/file/zupuremagakinomogomagig.pdfIn PDF document text
    • https://zoomkish.com/basefile/zoomkishcom/files/dizejarofok.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1612eeef16371c---nazumisowovolatut.pdfIn PDF document text
    • https://feltshoe.com/userfiles/file/nimoluj.pdfIn PDF document text
    • https://www.champagne-auge-dascier.com/ckfinder/userfiles/files/75977882673.pdfIn PDF document text
    • http://ez-surveying.com/htdocs/cljr/data/files/xaveverixidigojimofiroru.pdfIn PDF document text
    • http://peterpan1996.it/userfiles/files/kupezipanuzigazu.pdfIn PDF document text
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/6gjmmak8l57g1civlaa47lasqd/wuvulijujizanobefufitope.pdfIn PDF document text
    • http://kvbm.org/pds/userfiles/files/vudifumapupa.pdfIn PDF document text
    • http://studiostocchi.eu/userfiles/files/faxenufaxoliguz.pdfIn PDF document text
    • https://gaadalagi.com/contents/files/35211948646.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_off0000d10d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD10D 18048 bytes
SHA-256: ad1e0c92644a7683439fa8741a6a934906ba124c9e09709c1caeced0bbaf8722
font_01_sfnt_off0000ff7b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF7B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011792.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11792 10476 bytes
SHA-256: 375988c3148c574f0784a723fb1ceccaec718bc20d4faad4d7605ab985678fa4