Malicious PDF — malware analysis report

Static analysis result for SHA-256 31795bc4fbc83bda…

MALICIOUS

PDF

78.8 KB Created: 2021-03-14 10:05:57 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-20
MD5: 01285ae1fcc7fb9b10f2a1fe041e4f59 SHA-1: 0d3dfeb077584585567a2ef70a58fac6ec7c9a58 SHA-256: 31795bc4fbc83bdacac369c072863eb269249e65b63b1d63ddc26c533118e36d
186 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many pointing to disposable hosting, suggesting a link farm designed to distribute malware or phishing content. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of embedded URLs and the heuristic 'PDF_SEO_LINK_FARM' confirm the attack pattern of using a document to redirect users to potentially harmful sites.

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://kuzutuzo.ru/123?utm_term=medical+terminology+basics+packet+answers PDF link annotation
    • http://yellownatural.space/56604266753bih1i.pdfIn PDF document text
    • http://50offstore.info/35092282244rbt38.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393631/normal_5fda2a26d9832.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4463529/normal_601bcd3c1c857.pdfIn PDF document text
    • https://laxonetamaj.weebly.com/uploads/1/3/4/0/134096763/luweki_timuloremexefo_delopupikuwexek.pdfIn PDF document text
    • http://comforfemj.fun/loxosodobezevogakonalowe299lz.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387571/normal_5fdc029d7e5d1.pdfIn PDF document text
    • https://mateboxabivof.weebly.com/uploads/1/3/4/7/134763458/5714238.pdfIn PDF document text
    • http://cmb-eco.com/woodworking_bench_top_material4tgrb.pdfIn PDF document text
    • http://copyright-services-us.com/what_is_religions_role_in_society3vt17.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/napoledunadigo/73645183628.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/29802c7d-eda2-4a20-8aac-d9a1bc18c8e4/english_book_store_berlin.pdfIn PDF document text
    • https://3cd6846c-369c-4875-9c63-132df726a2dd.filesusr.com/ugd/7ab50f_d4ffa2f6b87044d29346ee1d209f19de.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/3507c573-dd93-41a7-a742-6ff171ed0a13/21461724299.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0c9e1547-766c-402e-be7d-5129bf141018/pezitemefalabikixugavug.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b83d5ae0-4578-4480-9472-617b491408d6/taco_bell_shredded_chicken_burrito_fresco_calories.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/eb4bbb1b-fcb5-4eeb-90a0-2c4431fd7ea6/how_to_fix_chest_freezer_not_freezing.pdfIn PDF document text
    • https://s3.amazonaws.com/fuzafuzeruwit/juxaputubipomibanaxo.pdfIn PDF document text
    • https://16012499-1299-48b0-8cdd-5f23a7749958.filesusr.com/ugd/fafc38_c9166f48cfbf42f38f0a0e8da1eb982b.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_off0000f5d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5D0 5796 bytes
SHA-256: 64900b7289df52f53edf2c8247e3e6c666fdb083db4f9465374661d69fa7031e
font_01_sfnt_off00010993.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10993 10568 bytes
SHA-256: 10cd1bb75e03beb7e4349efeb4190427109f47262215a9d15a1e662ddb42d122

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