Malicious PDF — malware analysis report

Static analysis result for SHA-256 a619289d7ebd54e3…

MALICIOUS

PDF

83.5 KB Created: 2021-04-19 07:44:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 5615c55708d9b4f806954780c8b83cf6 SHA-1: 3ff7f39153171b1bd1757ab95081c91ea274638a SHA-256: a619289d7ebd54e3d76e1f6ac74e5ad75211b53e3a3baa65e1af10396213ded0
186 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by a machine learning classifier and ClamAV. It contains a large number of external links, many pointing to disposable domains, suggesting a link farm or redirection scheme. One of the primary URLs extracted is https://jacksth.ru/strik?utm_term=is+gdp+per+capita+same+as+average+income, which appears to be part of a SEO manipulation or phishing lure. The document body is heavily obfuscated, preventing a clear understanding of its direct intent, but the overall structure and link farm behavior strongly indicate malicious intent, likely to redirect users to malicious sites or download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://jacksth.ru/strik?utm_term=is+gdp+per+capita+same+as+average+income PDF link annotation
    • https://piwomokoxik.weebly.com/uploads/1/3/5/3/135335333/8249484.pdfIn PDF document text
    • https://pedogore.weebly.com/uploads/1/3/2/8/132815008/9fbdb2a.pdfIn PDF document text
    • https://juzowugaf.weebly.com/uploads/1/3/4/7/134773334/907490.pdfIn PDF document text
    • https://lepoboniw.weebly.com/uploads/1/3/0/9/130969744/vanenax-najirurufesiluf.pdfIn PDF document text
    • https://xevezuwojuko.weebly.com/uploads/1/3/0/7/130740392/2211834.pdfIn PDF document text
    • https://cdn.sqhk.co/nadizolobe/jd5d7gg/checksur._exe_windows_7_32bit.pdfIn PDF document text
    • https://cdn.sqhk.co/ninulekuto/hjHgfz9/idle_bubbles_cannon_mod_apk.pdfIn PDF document text
    • https://wudizabilizone.weebly.com/uploads/1/3/4/7/134745746/0def0babc641d91.pdfIn PDF document text
    • https://xikematevi.weebly.com/uploads/1/3/4/3/134392378/damotirago_luvitigusamoj_pelajoda.pdfIn PDF document text
    • https://vofirojaj.weebly.com/uploads/1/3/1/6/131637635/3516460.pdfIn PDF document text
    • https://cdn.sqhk.co/zivupowixede/jhUZyfn/xawodele.pdfIn PDF document text
    • https://retinagarar.weebly.com/uploads/1/3/4/3/134319249/6d2b996ac9086.pdfIn PDF document text
    • https://dumaxenuwumav.weebly.com/uploads/1/3/3/9/133997891/e4c459.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/bulalowisu/implicit_differentiation_worksheet_for_calculus_1.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b9ac42b5-f60e-4549-b0a0-2b3998e77cb3/927002256.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/92c2047e-7557-4f7f-aa78-294f2b1bb02b/wuluxakerudarobisoteg.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2a051163-6278-4484-8052-e43b9614f302/allister_type_iia_garage_door_opener_parts.pdfIn PDF document text
    • https://s3.amazonaws.com/mavixu/casual_staff_employment_contract_template.pdfIn PDF document text
    • https://s3.amazonaws.com/bufexa/first_alert_p1210eaus.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/96573b99-d6ca-44e9-929b-2b93bce107c9/11476048965.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001080b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1080B 5356 bytes
SHA-256: 9f1d1b332d2fc640ff9d97bb8cad127a4dd7c5a7f658a50330c2e71808459903
font_01_sfnt_off00011a35.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A35 10692 bytes
SHA-256: 0eaa7389266f99ee0436d7fc0fa503ceee38f0b538283430e8f263880af0a6b0