Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd3fb7f080bfb297…

MALICIOUS

PDF

84.5 KB Created: 2021-05-26 16:21:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-16
MD5: 4e4f36f1a5be938c40855a00941f2155 SHA-1: b07f8c607f2b9092fb2884a52446e2369e8f934e SHA-256: cd3fb7f080bfb29708f7472c35832f18ce65266554ffa7e5626d9eb54cd27ce2
126 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. The document contains numerous embedded URLs, many pointing to disposable hosting services, suggesting a link farm designed to redirect users to malicious sites. The presence of external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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=cavalier+king+charles+spaniel+welpen+kaufen+bayern PDF link annotation
    • https://pusurezifokuni.weebly.com/uploads/1/3/4/3/134317864/9822542.pdfIn PDF document text
    • https://bofisolipog.weebly.com/uploads/1/3/4/4/134438855/2cc256.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4458635/normal_6034dd902e502.pdfIn PDF document text
    • https://kimukotepasa.weebly.com/uploads/1/3/5/3/135329918/0e42e4c10.pdfIn PDF document text
    • https://kifirazet.weebly.com/uploads/1/3/4/7/134715796/7454278.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4501356/normal_600fb0f3db34f.pdfIn PDF document text
    • https://dujizajep.weebly.com/uploads/1/3/4/7/134704211/ae9ca.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4409609/normal_6028e43884196.pdfIn PDF document text
    • https://kemusasozez.weebly.com/uploads/1/3/0/9/130969555/6010011.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387061/normal_602c89f45f4b3.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4475571/normal_60006dee6188e.pdfIn PDF document text
    • https://judozolu.weebly.com/uploads/1/3/1/4/131407514/zojuv.pdfIn PDF document text
    • https://wotopegajoxife.weebly.com/uploads/1/3/4/0/134042499/patokazibap.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4491671/normal_600ca5bb10587.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4478669/normal_606d8f5702b5b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4374189/normal_600c0b7660ced.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4446147/normal_5fdd225b16d22.pdfIn PDF document text
    • http://cavalier-king-charles-spaniel.info/In PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/c8e7d9fe-304f-4c08-ac76-1e78644bf130/how_to_turn_on_a_boiler_furnace.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f9a96653-08da-48d4-96a4-8d800c1d0da0/how_to_auto_top_up_ezlink.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
    • 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_off0000f08b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF08B 5640 bytes
SHA-256: 2571417d61fecc022640c67d156e1edf9e76bb839537c154199d68f2cbd93d64
font_01_sfnt_off000103d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103D9 12544 bytes
SHA-256: b5f64965117e12108b15949e6aad1be8f2f6647d037fd8f72a42626159005c1f
font_02_sfnt_off00012d4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D4D 16036 bytes
SHA-256: 35d3440dae1ebc896564e4e6f70ea95aa3a30a1ac603c7fffbb21b68b8b72e2f