Malicious PDF — malware analysis report

Static analysis result for SHA-256 a91e4cf80d493b3f…

MALICIOUS

PDF

91.7 KB Created: 2021-03-22 01:09:56 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-20
MD5: affc7caad3f461d56be0399fcea172ab SHA-1: 2f86762aed08c4add995924c1a44977d4e4780e3 SHA-256: a91e4cf80d493b3f547b3056ed72b7528c98e142fb0a66570148eb134d874c00
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 User Execution: Malicious File

The PDF file contains a large number of external links, many pointing to disposable hosting domains, indicating it functions as a link farm. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for SEO manipulation or to distribute further malware. The embedded URLs and the PDF structure are consistent with a phishing or spam campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://nipisod.ru/wix?keyword=owl+pellets+food+webs+and+pyramids+answers PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4485929/normal_60017e599db81.pdfIn PDF document text
    • https://cdn.sqhk.co/kexofodatop/j8zohjB/emotional_freedom_technique_online_certification.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4392470/normal_5fe64bdd52652.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4460694/normal_600b235690147.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4371814/normal_601432bcd70c7.pdfIn PDF document text
    • https://cdn.sqhk.co/gagunewatevo/MvjcUmi/juventus_player_wages_2018.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490371/normal_5fd2586303f65.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4448540/normal_601e0284aeee2.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4408009/normal_6008e224949f1.pdfIn PDF document text
    • http://vakotuwudar.22web.org/buradalaguzit.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4460063/normal_60209da40d057.pdfIn PDF document text
    • http://tizakeguwowil.22web.org/21558080080.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4473044/normal_6054f8e4a40ac.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4496374/normal_6040002dc6b3f.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://lajexexetawibo.rf.gd/dedube.pdfIn PDF document text
    • http://danijikuguwidak.rf.gd/97178611770.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9d00299a-ced4-4d5f-8846-bf23ad136044/72998310573.pdfIn PDF document text
    • https://8a5a474a-a671-4857-921d-d1df0ee72544.filesusr.com/ugd/523716_1aec16ecc8954f79843a38a52b834e75.pdf?index=trueIn PDF document text
    • https://6e229dea-1f83-4be8-8cd3-388eabd4f5e3.filesusr.com/ugd/1cfe37_0e092af367e3455389bd3164715fbddb.pdf?index=trueIn PDF document text
    • https://d52369c8-37f2-40d9-9d5f-d682b3b4a2e4.filesusr.com/ugd/6d5a7b_6a8af78b5f3144b9aca568b4ac432cda.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/702e2163-9b98-4d40-b1ac-bb083bc1f529/the_universe_next_door_chapter_10_summary.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c973724b-aa1b-476d-bba7-6c4fbdcef73d/nra_membership_free_range_bag.pdfIn PDF document text
    • https://9df6fdd8-df71-43fb-87ad-b121b2de7416.filesusr.com/ugd/e0d0cf_83c54e4c226a4e60a3b342fb400e42a8.pdf?index=trueIn PDF document text
    • http://widafasamuj.epizy.com/bodirus.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_off00012874.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12874 5548 bytes
SHA-256: e57fd4d6bfd477c2572d1a501fd49c41489204a00a8431844d6adedf7c58de27
font_01_sfnt_off00013b4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B4C 11096 bytes
SHA-256: 4de855d8d11a9aa603b3fadc88afcf48c47b271ec68f0d80d56e9cacd8440d50