Malicious PDF — malware analysis report

Static analysis result for SHA-256 50605be28ca39691…

MALICIOUS

PDF

67.1 KB Created: 2021-05-12 09:45:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-14
MD5: 789d70c9167c07ca292387187bd2d06b SHA-1: 9234fc2241eae74eb3a1220712635de84d69c497 SHA-256: 50605be28ca396919febfa388e8c2f0b3d9a516b8606011771042097be038388
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains a large number of external links, many pointing to disposable hosting, suggesting a link farm designed to redirect users to malicious sites. One such URL is https://jottigo.ru/strik?utm_term=prentice+hall+gold+algebra+1, which is likely part of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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://jottigo.ru/strik?utm_term=prentice+hall+gold+algebra+1 PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4418746/normal_5fe125127e0c2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4464715/normal_601e6d30d286e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4501204/normal_601eb4432ed6c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4475572/normal_601f5e2b50e94.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4387709/normal_5ff558080815b.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://9e2901ea-5d25-41a5-867c-54d0774c6e48.filesusr.com/ugd/4d0f37_3ba1c4b10d5849f2aa798ec9af16103a.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/a1e257d7-9a45-4b2e-a1ce-bb6c48e3bf50/50810208487.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f472e969-3aa2-46e5-ac60-7ac7d68f54b7/votisibo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c5596636-602a-4782-98eb-a06123031713/99973957027.pdfIn PDF document text
    • https://s3.amazonaws.com/dusubonifu/pewiwasekulejimarom.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/88b56941-65dd-47ff-b1f0-a2bc1981631d/23364884309.pdfIn PDF document text
    • https://s3.amazonaws.com/pulujolatepuv/unit_4_vocabulary_from_latin_and_greek_roots_answers.pdfIn PDF document text
    • https://3315be42-5dab-4b6e-b44d-105cb490973e.filesusr.com/ugd/2e3488_9e0e110b1261436ca948e97ed23ad641.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/zesixefe/borej.pdfIn PDF document text
    • https://s3.amazonaws.com/sugowubuf/48920610905.pdfIn PDF document text
    • http://rarazimefuv.rf.gd/bema_judgement.pdfIn PDF document text
    • https://s3.amazonaws.com/rubidokezive/intracerebral_hemorrhage_treatment_guidelines_2016.pdfIn PDF document text
    • https://df9240ce-57b4-430e-a582-521170ca5232.filesusr.com/ugd/10b03a_b38aaaf0a58d4f119b4c3bd0ec510641.pdf?index=trueIn PDF document text
    • http://dadewom.epizy.com/irobot_roomba_595_battery_replacement.pdfIn PDF document text
    • https://d4f4546a-a836-4b3d-8651-c56b89608eca.filesusr.com/ugd/3e9e83_92764c9e1627478b970a910eaceb42f1.pdf?index=trueIn PDF document text
    • https://5663e088-3595-439c-971a-5873693bee35.filesusr.com/ugd/e98895_6388f4a235244fbdaff960047151e7b0.pdf?index=trueIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cbcb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBCB 5216 bytes
SHA-256: 660a206a75867e24393d22afea347f1f8adb3bba8102c72f87e08768391b3144
font_01_sfnt_off0000dd7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD7F 9908 bytes
SHA-256: 4ad2d841a99f69938dc6fddc73d23cbef2dfd062a0cd565ef8a0ca046c2f8df9