Malicious PDF — malware analysis report

Static analysis result for SHA-256 be77cb4a7039f638…

MALICIOUS

PDF

71.6 KB Created: 2021-04-29 14:13:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: 912f9d2a37f76c2a3853baf316e2ef4f SHA-1: 4422265a4f8e62c3336bf2ac530f25adf409c888 SHA-256: be77cb4a7039f63864682e38f881005b46e6471b108ac5833d4a9dfc991c95ae
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF 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 CMS upload storage, suggesting it's used for distributing further malicious content. The embedded URLs, despite some being marked benign, are part of a pattern to redirect users to potentially harmful sites, likely for phishing or malware delivery.

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 https://www.helpagesl.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608963eac60fc---dunodewapefesuji.pdf In PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607fa17aa0944---48257574911.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608138cbd5b40---72619231159.pdfIn PDF document text
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/7a88507df0f88dbc19df9016773a0014/82485462677.pdfIn PDF document text
    • https://mamproducciones.es/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb24f8c175---kegalefexajoxiwofi.pdfIn PDF document text
    • https://aquariumfargo.com/wp-content/plugins/super-forms/uploads/php/files/14de1835d96aa9e2c78ee4d950c4a4ee/gawomam.pdfIn PDF document text
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607981f606775---febudewirebalosulubakup.pdfIn PDF document text
    • http://afghansolar.com/userfiles/file/7447373002.pdfIn PDF document text
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/b56de8ea55855a1a69aa0ad4638c89b1/solelemibovano.pdfIn PDF document text
    • http://www.iqubz.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a9e54988c0---lutitefenagugekab.pdfIn PDF document text
    • https://markzone.az/wp-content/plugins/super-forms/uploads/php/files/1pta471ktll338so7ibfk4vp3a/37518881602.pdfIn PDF document text
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/e3l6ook2tfhvdvdb8ecgup147q/42794538900.pdfIn PDF document text
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/16077ffe3ef4f5---nerodajazesoxovekinudo.pdfIn PDF document text
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16080289278bf0---87124175610.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/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=bt+smart+hub+installation+guidePDF 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_off0000d934.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD934 5428 bytes
SHA-256: 7efd5d78067a0904c77c12204b81cad0213b0175ac944e3495b84baff9908c21
font_01_sfnt_off0000eb78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB78 10752 bytes
SHA-256: 4d356d704ff1952a60eeb0da7ce9e2845fe1206c691f3874251cdec7d6b4201b