Malicious PDF — malware analysis report

Static analysis result for SHA-256 3cf27cb79d7803ce…

MALICIOUS

PDF

70.2 KB Created: 2021-09-26 13:55:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: f614273187b8c5b4fca82b7b4d12b429 SHA-1: 665b350111d792c0fa69e2206047f49c49b2d5e2 SHA-256: 3cf27cb79d7803ceb8c9d4c7d188f5cf9c60fcd438c0ba18a92f198c5d8e4f2a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS platforms. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure and heuristic firings strongly suggest an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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.protectakoteasia.com/ckfinder/userfiles/files/1549825509.pdf In PDF document text
    • https://smartstone.ca/userfiles/files/3904786750.pdfIn PDF document text
    • http://top-caster.com/userfiles/file/bujukatojudi.pdfIn PDF document text
    • https://journeypeople.cc/wp-content/plugins/super-forms/uploads/php/files/638997637a84bf7a8b68665e59c2c9d1/11389289086.pdfIn PDF document text
    • http://xn----dtbhwhggdaoqfh3d.xn--p1ai/media/file/65712627367.pdfIn PDF document text
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614901a84182b---82751691552.pdfIn PDF document text
    • https://tarzminder.com/resimler/files/xegomupobuviwiwe.pdfIn PDF document text
    • https://theurbanthinktank.com/files/25673031314.pdfIn PDF document text
    • http://mgtofubbq.com/uploads/files/rukasidawotirukimodox.pdfIn PDF document text
    • http://architettobotteonpierpaolostudioabacus.it/userfiles/files/89855878692.pdfIn PDF document text
    • http://terezmisszio.eu/files/file/59277850789.pdfIn PDF document text
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/uhe96ev2gelvprdv37dnamsine/79315262242.pdfIn PDF document text
    • http://chiari-web.com/ckfinder/optimist/files/tinavopufavobi.pdfIn PDF document text
    • https://globalybm.com/ckfinder/userfiles/files/1630655351.pdfIn PDF document text
    • http://kayapalinakliyat.com/file/55626168968.pdfIn PDF document text
    • http://alhouti.com/userfiles/file/vatolofab.pdfIn PDF document text
    • http://apartmany.cucoriedka.sk/data/files/zuzisiwamikumajowum.pdfIn PDF document text
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b9bbbdf67b---20958495988.pdfIn PDF document text
    • http://davidhammerstein.org/userfiles/file/3737099076.pdfIn PDF document text
    • http://generale-bureautique.fr/gdb/files/file/39356681931.pdfIn PDF document text
    • http://bjsddesign.com/filespath/files/20210905133303.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=unblocked+games+roomPDF link annotation
    • http://s292376414.onlinehome.fr/datas/imgmail/file/jizimi.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_off0000b143.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB143 10764 bytes
SHA-256: 3926a682d119de26efbd8ec20795f7424defb2c478b6deafaeb8c85137fce2b4
font_01_sfnt_off0000c9cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9CB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e1dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1DD 15992 bytes
SHA-256: fd95965ea13e99bad203ca6054f9882911353b879a0a4a84622cfe38b9d8619b