Malicious PDF — malware analysis report

Static analysis result for SHA-256 503add914cf34167…

MALICIOUS

PDF

69.6 KB Created: 2021-05-14 11:43:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 79b50c3c6a33f638b079494eeaa26d3a SHA-1: 6215fe3c26117c8c2b51c53ca370a5e2f99b0c0d SHA-256: 503add914cf34167ac5bd720aea7eeb3554ba9ab52336a6916f35cff78c1fdd2
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, directing users to download files from compromised WordPress sites, disguised as a VPN browser APK. The presence of multiple links to disposable hosting and the use of UTM parameters suggest an attempt to obscure the true destination and potentially engage in SEO poisoning for malicious downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://bestmiamiturf.com/wp-content/plugins/super-forms/uploads/php/files/35b99605f1e8073b6c65353ee11321bd/pojuriw.pdf In PDF document text
    • http://dodici12.ru/wp-content/plugins/super-forms/uploads/php/files/vemj9a18gtnc9j6r4681crosk2/xavawojijabegesofuwo.pdfIn PDF document text
    • http://vilaportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080ef81893c4---41667569117.pdfIn PDF document text
    • http://asalsold.com/wp-content/plugins/formcraft/file-upload/server/content/files/160825e3e7fc6a---81437760834.pdfIn PDF document text
    • https://akarchlight.com/wp-content/plugins/super-forms/uploads/php/files/5c8caaced729e608e8f3c0a90f51fd1e/61196943242.pdfIn PDF document text
    • https://m-co.de/wp-content/plugins/super-forms/uploads/php/files/7m764pa01k81t1u7d08vg7p9cb/fevevexolujifutidurojam.pdfIn PDF document text
    • http://www.itbaloch.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb08c81d1a---gobenedivutabusorilos.pdfIn PDF document text
    • http://www.marcado.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1607cfc6f844d7---81732725123.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087defa87580---38983939078.pdfIn PDF document text
    • http://anaminfo.com/attachfile/file/fidujenoj.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607a734919daa---muxibe.pdfIn PDF document text
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091060bb459f---28558718867.pdfIn PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/1608d8b6d16a18---fajubujewimu.pdfIn PDF document text
    • http://uat.ideadunes.com/projects/ideadunes-portfolio-site/wp-content/plugins/formcraft/file-upload/server/content/files/1607f309084a7d---88559206837.pdfIn PDF document text
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/16076b2b753dfb---22189527678.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=vpn+browser+apk+for+pcPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d32b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD32B 5236 bytes
SHA-256: 98c5343defe2dbf63f4b04b2df05bb9af5515244c6f290111f1e7906c8f3bdbc
font_01_sfnt_off0000e525.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE525 10784 bytes
SHA-256: 7089556d9a1036e3997fe6cefa07f053e034145584475d6bda80cee8a93e8fa4