Malicious PDF — malware analysis report

Static analysis result for SHA-256 8672f9e1943cb0bc…

MALICIOUS

PDF

74.3 KB Created: 2021-06-06 21:13:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: f890447c67ec034cf98382bd7a808ef0 SHA-1: 532d0c8dd199dfc0bfa894e7c5c71327e759b903 SHA-256: 8672f9e1943cb0bcbc0399dbcfddd08fb76d3b1a6caf9248d1c18e76dbe71222
186 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. It functions as a link farm, containing numerous external URIs, with one notable example being https://ketchas.ru/pbw?utm_term=houston+free+chat+line+numbers. The presence of a link farm on disposable hosting and the high number of external links suggest an attempt to distribute traffic or potentially engage in phishing or SEO manipulation.

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://ketchas.ru/pbw?utm_term=houston+free+chat+line+numbers PDF link annotation
    • https://garotilalu.weebly.com/uploads/1/3/0/7/130739336/kapumudezarebisa.pdfIn PDF document text
    • https://fejenugid.weebly.com/uploads/1/3/4/0/134016750/1843854.pdfIn PDF document text
    • https://silodadut.weebly.com/uploads/1/3/2/7/132712229/femetusixariraje.pdfIn PDF document text
    • https://vekibapovadivoz.weebly.com/uploads/1/3/0/8/130873848/a1d510a646e2b7.pdfIn PDF document text
    • https://fufiwixafuwisu.weebly.com/uploads/1/3/4/7/134770326/f202a3.pdfIn PDF document text
    • https://pezibusogesa.weebly.com/uploads/1/3/0/7/130739584/lumiwatarad.pdfIn PDF document text
    • https://nupepapuk.weebly.com/uploads/1/3/1/4/131484133/b01a3e884cdf53d.pdfIn PDF document text
    • https://rasofenetiko.weebly.com/uploads/1/3/4/8/134862321/5286042.pdfIn 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/abf5ca09-3575-4ca5-963f-beccfd9e6928/harry_potter_free_online_games_dueling.pdfIn PDF document text
    • http://pikalunik.pbworks.com/w/file/fetch/144693051/sikuretixororasivu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/deed4c26-137c-4b0b-86b7-a9f1e6812345/what_are_the_side_effects_of_hyperbaric_oxygen_therapy.pdfIn PDF document text
    • http://mapijakemifo.pbworks.com/f/fasodorisixorizaguvix.pdfIn PDF document text
    • http://nagomax.pbworks.com/f/91002820468.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/deaf9013-b316-4b5f-becf-50a1bcf539f6/dirorofusapudupofifep.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c3eff06e-d9d9-4461-bd45-ebc3bb8d5746/how_to_use_yeti_microphone_with_xbox.pdfIn PDF document text
    • http://tijigika.pbworks.com/f/how_to_program_a_ge_universal_remote_cl5.pdfIn PDF document text
    • http://nagaxop.pbworks.com/f/lugar_mitocondrial_donde_se_realiza_el_ciclo_de_krebs.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8aacd7d5-4845-4e16-b466-b2549f57b611/problemas_en_paraiso_chapter_4_summary.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/af4d0013-0045-4a69-b44f-0da761296d73/examenes_lengua_5_primaria_santillana_saber_hacer_contigo.pdfIn PDF document text
    • http://kafunujazuwo.pbworks.com/w/file/fetch/144726402/zafaxokugivenipimuvenel.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_off0000e7f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7F7 5220 bytes
SHA-256: 00811a3686cca10f8da723e9d33f95d4ed62c8b36a51ba917f215e4ad69e7eb0
font_01_sfnt_off0000f992.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF992 10060 bytes
SHA-256: 26de6d0f1c8d66b093310b813e8becb99c43c42c970131131874ed061776b592