Malicious PDF — malware analysis report

Static analysis result for SHA-256 c55b35eb10099b97…

MALICIOUS

PDF

90.5 KB Created: 2021-04-17 18:06:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-07
MD5: 9fe5ee8d61fa431d0d49e8e3b390f290 SHA-1: 1b93afd26c251b64c12a1fed59b7acace2bfcd76 SHA-256: c55b35eb10099b9732ea541ff2a5971377d7f01bedb836825370787aaa1e0861
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 hosted on disposable domains, suggesting a link farm or SEO spam campaign. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and numerous external links point towards an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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=delonghi+ec155+leaking+water+underneath PDF link annotation
    • https://damosekim.weebly.com/uploads/1/3/4/2/134235752/e8360b25.pdfIn PDF document text
    • https://visosoduvevup.weebly.com/uploads/1/3/4/2/134234588/dagolixutujob.pdfIn PDF document text
    • http://xizuwekimexuwag.22web.org/jinedokenuwamuta.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403946/normal_6021aad017e16.pdfIn PDF document text
    • https://jogexolo.weebly.com/uploads/1/3/5/9/135957561/fexavofemamer_bexubugivosuj_zogimivemoreg.pdfIn PDF document text
    • https://vatipasa.weebly.com/uploads/1/3/0/7/130775610/1be66ed.pdfIn PDF document text
    • https://piramejujidizek.weebly.com/uploads/1/3/4/6/134694247/6475112.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4417806/normal_5fcee3e20a831.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://sofiwige.rf.gd/komitukofelelugiku.pdfIn PDF document text
    • http://pulawev.epizy.com/byung-_chul_han_burnout_society.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/47cc9e11-151b-4564-bcca-871799060b11/my_vedic_moon_sign.pdfIn PDF document text
    • http://mafixatoje.epizy.com/peer_influence_on_academic_performance_research_paper.pdfIn PDF document text
    • http://famekemij.epizy.com/3_day_potty_training_manual.pdfIn PDF document text
    • https://973697ad-ffa4-4f9d-85cd-0c9d1ea039ee.filesusr.com/ugd/5f5755_e449c9e01ec044319048f8cf19c8a772.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/xezonijida/20318567386.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ffff6676-3e5e-4677-8099-106be28829b9/stephen_abbott_understanding_analysis_2nd_edition.pdfIn PDF document text
    • https://f8071fb1-33dc-4bb9-9fe9-292e0ca0d861.filesusr.com/ugd/253000_1ac9bd718b3f44dfbf68c1eb2222b1ca.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/numunenoji/the_very_busy_spider_activities_tes.pdfIn PDF document text
    • https://a95edb9d-21e5-46e4-bb1b-b1fdf66a5dae.filesusr.com/ugd/09e34a_fce933dc70e44a13abc6532efb412354.pdf?index=trueIn PDF document text
    • https://63aa7d51-6c54-48cc-ac87-b710a0da19c3.filesusr.com/ugd/c8d394_424ed57cad80478f9ee994777a71c46b.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/3fe2ae4b-fa31-402f-96d9-fc1eea4266b7/lord_of_the_flies_study_guide_chapter_7.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2753736e-bd00-4ada-9b62-5afe03777953/nofodukabinosuxowureb.pdfIn PDF document text
    • https://8bd0dbf5-62e0-4684-a95a-1d9666dfa34a.filesusr.com/ugd/e71694_238ad1cd0e2d47d8a25ee977531e6aff.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
    • 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_off0001099a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1099A 5352 bytes
SHA-256: d837e6df506ea4fb2944b37abb7db64b00ec77ec4acd7f284d61434866cff708
font_01_sfnt_off00011be7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BE7 10644 bytes
SHA-256: bc4bcb5532154e20267fb5c07bf3132859c25a994501370b4e8c1194d070dc39
font_02_sfnt_off0001403c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1403C 18152 bytes
SHA-256: 99f057fe1c5ad7f6aba5a41a421269d4b3242e5559bb260bf70c39b7429001cd