Malicious PDF — malware analysis report

Static analysis result for SHA-256 b52a0d3fe1fdf766…

MALICIOUS

PDF

87.8 KB Created: 2021-09-19 08:23:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: e256547c5bb0ee702a25e6e19cf04aaa SHA-1: 23cddd9d96c2918c636cb6acf967cedfa844614f SHA-256: b52a0d3fe1fdf766d21af897a87f21a65a3d0fb1b8e6a838f44b025616156807
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm pointing to compromised WordPress uploads and disposable hosting, suggesting a phishing or malware distribution scheme. The embedded URLs, while numerous, do not provide specific content, reinforcing the idea that the document's primary purpose is to redirect users to external malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://tokyoracing.hu/userfiles/file/vedoxena.pdf In PDF document text
    • https://tecnicadovolante.com/images/file/52961755405.pdfIn PDF document text
    • https://zenmobile.in/jaipriyart/uploads/files/kujige.pdfIn PDF document text
    • http://deurwater.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c7f73c64d6---31739477713.pdfIn PDF document text
    • https://acgroupenterprise.com/userfiles/file/mewexulur.pdfIn PDF document text
    • http://gyndoktors.de/ckfinder/userfiles/files/59352575157.pdfIn PDF document text
    • https://kimcert.org/E/file/vowoxazezegezifobuzik.pdfIn PDF document text
    • https://riolospettacoli.it/filesUploads/file/32162816377.pdfIn PDF document text
    • http://31kouqiang.com/userfiles/file/1631722117.pdfIn PDF document text
    • http://gsemilia.it/userfiles/files/68283495278.pdfIn PDF document text
    • http://www.veronicaneal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/16131a5251d653---67591139095.pdfIn PDF document text
    • http://1-cities.com/blog_images/blog_/file/75565529901.pdfIn PDF document text
    • http://hkbroadwin.com/userfiles/63291424156.pdfIn PDF document text
    • https://travelsafeway.com/userfiles/file/jojoviwoles.pdfIn PDF document text
    • https://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1614164cd6a443---xivufujoludetepa.pdfIn PDF document text
    • http://emeat.ru/var/files/27173625401.pdfIn PDF document text
    • https://vicareyou.com/userfiles/file/falanijomosejizum.pdfIn PDF document text
    • http://russia-ex.com/images/blog/file/mirepopekomazogojozupip.pdfIn PDF document text
    • https://bindazzled.com.au/wp-content/plugins/super-forms/uploads/php/files/341d9a751864937bdfde9e5074b5d143/jurifalizinex.pdfIn PDF document text
    • http://www.77ice.com/upload/files/mitusonivubujopujoxutuze.pdfIn PDF document text
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1613cb35aea89a---26051776073.pdfIn PDF document text
    • https://www.c2commercial.com/wp-content/plugins/super-forms/uploads/php/files/11e6474fee2ba2b3bc8ecfe29a714c65/81596339303.pdfIn PDF document text
    • http://studiodebiaggi.eu/userfiles/files/69097483119.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=rog+phone+5+android+12PDF 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_off0000f170.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF170 18308 bytes
SHA-256: 683888b7e4c8ef56b2e368e8e51890834517cd32eee4c614c79570f7929f6cf8
font_01_sfnt_off000120ed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120ED 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013904.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13904 10712 bytes
SHA-256: d4b11847d738b60ca96e34dfc088e58e840d6af74cdc38c43e09815af6dc53c8