Malicious PDF — malware analysis report

Static analysis result for SHA-256 b5c8cf9c54bdb4c0…

MALICIOUS

PDF

85.2 KB Created: 2021-03-31 20:11:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 9a428bf71e4ea6c3c256241a4f1c3ae0 SHA-1: 49248aa5862a41231248fcda66e57891dc18dae0 SHA-256: b5c8cf9c54bdb4c013f54c0e137cf36e3ae46ed2165edc3997762010fae76b62
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which point to disposable domains, indicating a link farm designed to manipulate search engine results. The primary URL, 'https://gimoguvi.ru/award?keyword=biological+oxygen+demand+procedure+pdf', suggests a lure to disguise malicious activity. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution.

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://gimoguvi.ru/award?keyword=biological+oxygen+demand+procedure+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4378165/normal_605f9dbc4bf36.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4475203/normal_5fe182c35defd.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4446512/normal_6005ecb86e165.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4402533/normal_5ff6a366a287c.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4472764/normal_5ff2cbcd4f8ca.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4414847/normal_6024bc4de9ca4.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4446502/normal_5fdf487d0a64d.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/bbcd9a50-61d6-468c-ad96-5af9d2f30cd9/sinners_in_the_hands_of_an_angry_god_literary_elements.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e34261ef-0eda-4d2f-96d7-20ac0676d273/do_tessa_and_trevor_get_together_in_after_we_collided.pdfIn PDF document text
    • https://1864c106-1a4f-4194-99fb-dabd5a0af450.filesusr.com/ugd/17b194_1f2822df89684ba6989fa82fd8e35a19.pdf?index=trueIn PDF document text
    • https://d525ee04-2a40-494f-8ba9-fee52f7b18ee.filesusr.com/ugd/8b8e24_5a27eafd80464d328c57c26e950a2a5a.pdf?index=trueIn PDF document text
    • https://5849b288-062f-49f8-a71b-da420f1f00fd.filesusr.com/ugd/c068f8_217f2c7514b84211a77b835eff442b01.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/10901044-7295-4f9b-9104-800d53c31eaf/how_much_do_belotero_injections_cost.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f781974b-d4f7-4f98-b566-181c637901cc/gaxekekonurad.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5a6e8e3a-3f21-4f35-9f66-7d4c61532640/bejijimaterifawesu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/409ab72d-bd77-4af7-8c58-4c3c1192d2fe/examples_of_domino_theory_of_accident_causation.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1e5602ea-da5d-4435-92e9-113a352e73fd/de_que_trata_la_odisea_resumen_corto.pdfIn PDF document text
    • https://147762ec-90f0-4523-8579-43cb3cd17c82.filesusr.com/ugd/6c48b9_385fc59fae8143c3b71ceb5be62a4b53.pdf?index=trueIn PDF document text
    • https://83372c7a-1065-4b07-8284-b64562b46e84.filesusr.com/ugd/035489_74f3cf6d3f9b4ce1a9a954681c143fec.pdf?index=trueIn PDF document text
    • https://e216d865-ddc7-438b-99b2-64609380b1bb.filesusr.com/ugd/7ae8b3_39cd249a63c0449387e6b7a1cd00d4de.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_off00010fe7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FE7 5516 bytes
SHA-256: 0dd2ce4654a80284f7044197c4f0b547eb1358cc4b6203384cc4edf7e8e64473
font_01_sfnt_off000122a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x122A6 10684 bytes
SHA-256: 20eaa7fc05e22c3e2b9b662938a175821101ab10d7ba0154f7391ac3ce37241f