Malicious PDF — malware analysis report

Static analysis result for SHA-256 1f3f82720b51f1d0…

MALICIOUS

PDF

75.1 KB Created: 2021-05-08 04:26:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 6621bc485fb6c89ffa65cff0b44b0bc7 SHA-1: e75971fbbf0e6f5bdf657f51423ad421c5b085ee SHA-256: 1f3f82720b51f1d0612270b9af6cde2593dd2380d1a4fe37108c3caf7ceae80c
226 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a lure related to remote support tools, but the primary function appears to be a link farm hosted on disposable domains. The heuristic 'PDF_SEO_LINK_FARM' indicates a large number of external links, many of which are on disposable hosting, suggesting a malicious intent to redirect users to potentially harmful content. The ML classifier and ClamAV detection further support the malicious nature of the file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • Remote-support tool lure high SE_REMOTE_SUPPORT_LURE
    Document instructs the user to install, open, or connect with a remote-support tool such as AnyDesk, TeamViewer, Quick Assist, or ScreenConnect — high-risk in an unsolicited document
  • 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://botokaw.ru/strik?utm_term=how+to+use+propresenter+remote PDF link annotation
    • http://nogeturafo.sportsontheweb.net/18553587944.pdfIn PDF document text
    • https://cdn.sqhk.co/sirepajaku/whjUrji/faliwosuwefimotujawu.pdfIn PDF document text
    • http://plafond.xyz/nietzsche_twilight_of_the_idols_gutenberg12cmz.pdfIn PDF document text
    • https://cdn.sqhk.co/dujagazatad/ijcMgc8/zonudenegimazu.pdfIn PDF document text
    • https://xowilululevala.weebly.com/uploads/1/3/4/0/134017879/512dae854fec0e.pdfIn PDF document text
    • https://nofefikow.weebly.com/uploads/1/3/4/5/134510094/3804520.pdfIn PDF document text
    • http://urro-hu.com/how_to_write_a_compare_and_contrast_essay6oomw.pdfIn PDF document text
    • https://tapidokebijimub.weebly.com/uploads/1/3/4/5/134577153/muvigodavobi.pdfIn PDF document text
    • https://wunepilupizuxo.weebly.com/uploads/1/3/1/8/131857535/2227462.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://temodorofeg.atwebpages.com/capricho_arabe.pdfIn PDF document text
    • https://ff366fda-cde0-4b3b-b256-8a43afed25ec.filesusr.com/ugd/b3318b_c5fd93872e404928876116496d0cd784.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/c865b4b1-28c3-4495-ab01-0a0c4aa8f389/mfc_9970cdw_check_toner_level.pdfIn PDF document text
    • http://tuminexozuvino.atwebpages.com/engineering_mathematics_gate_notes_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/59319172-9bc0-4a97-8065-75d40fc1623d/wezobebak.pdfIn PDF document text
    • http://gixiluvigatekij.atwebpages.com/zewugiroperisupazano.pdfIn PDF document text
    • https://1618b3f4-dcc0-4047-a816-eeb1cbe43c51.filesusr.com/ugd/a01749_67d5a671c29349dca1baff43942eead9.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/89d0ea36-880f-4d61-9159-fbaa8b5a884d/canon_mx432_printer_ink_cartridge.pdfIn PDF document text
    • https://c07b3cb0-7d4a-4e65-9c62-eb3bd0ce3b6b.filesusr.com/ugd/7560d5_c9f1a0fc9cea4d558df22f98d25d3819.pdf?index=trueIn PDF document text
    • https://fa0867c9-8cf0-46f9-bfae-aad8e49c21f3.filesusr.com/ugd/cdba2c_59a9013119984652823a38a8e39a45a0.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_off0000eafa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAFA 4776 bytes
SHA-256: 4bba3fc0352e8dc595e27bd8117685fecbd286f3c7d0945dd6fa8d0ebc0a749e
font_01_sfnt_off0000fb31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB31 10440 bytes
SHA-256: f4cd096e6755dcb2d2a0c3ea1d00e0d44dde2ae7cf0bf8ed482e56816321593c