Malicious PDF — malware analysis report

Static analysis result for SHA-256 5f153c1dd70eab2d…

MALICIOUS

PDF

88.8 KB Created: 2021-07-27 11:49:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: ef8bfa88eb0436cb0822800bdb9876fd SHA-1: af5b20bd45dd650cd007e4c0b2d4b18c56348f20 SHA-256: 5f153c1dd70eab2d701c1182c7aea58cce3f6090a09544bdadd317481aee77b6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. While no scripts were explicitly extracted, the PDF structure and link farm behavior are indicative of a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://xn--80akazwaeiw.xn--p1ai/editorfiles/file/7423476551.pdf In PDF document text
    • http://jrpst.pl/userfiles/file/torisatezajadotu.pdfIn PDF document text
    • https://hcs1000.org/wp-content/plugins/super-forms/uploads/php/files/394465db14de321f9cf6683818a47cfd/82904039827.pdfIn PDF document text
    • http://nuyewrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/c0e2f3abfbbb7b8a6c75eda450688bf0/zujoke.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c704beba44f---50809384157.pdfIn PDF document text
    • https://artsketch.ru/wp-content/plugins/super-forms/uploads/php/files/8f6a925dd7ea3f5e34309c6cbde85b50/nezub.pdfIn PDF document text
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/16084c7c2eae99---90657138829.pdfIn PDF document text
    • https://markzone.az/wp-content/plugins/super-forms/uploads/php/files/8v2fa3s99lj55df7uhh3m8hkqa/vizobepusukibebofemu.pdfIn PDF document text
    • https://arabacioyunlar.com/calisma2/files/uploads/70524453196.pdfIn PDF document text
    • https://phucatgarment.com.vn/ckfinder/userfiles/files/96144850879.pdfIn PDF document text
    • http://alternativefitness.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160717ab2e02cb---mabanajubujizosodewonu.pdfIn PDF document text
    • http://vendingchat.ru/uploads/ckfinder/files/xofomitebuvogotali.pdfIn PDF document text
    • http://vlajamo.cz/images/file/jesosawupawonot.pdfIn PDF document text
    • http://first-group.kr/ckupload/files/28320989229.pdfIn PDF document text
    • https://grandplaza.bg/uploads/assets/file/xenagukenutakosap.pdfIn PDF document text
    • https://thewentworthco.com/wp-content/plugins/super-forms/uploads/php/files/ml6glfhkmh4vo3rp7abtshh192/55661203874.pdfIn PDF document text
    • https://hifi-markt.eu/kunden/kronhardt/ckfinder/userfiles/files/53743031398.pdfIn PDF document text
    • http://timatey.kz/wp-content/plugins/super-forms/uploads/php/files/m2k3dqqp04m8p0i073n1jekkf4/kabade.pdfIn PDF document text
    • http://thaiboxes.com/piceditor/file/58929000373.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=how+to+know+if+it+is+a+blighted+ovumPDF 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_off0000f760.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF760 16740 bytes
SHA-256: 245a21277c15786798614137c09f1c9ffa384835ca12f851d3143b3c98de2642
font_01_sfnt_off00012314.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12314 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013b2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B2B 11176 bytes
SHA-256: 04c0dd7b9952ae66cce36750b3b6190f7ab52357ce2dca9f52e61026e9b9afd4