Malicious PDF — malware analysis report

Static analysis result for SHA-256 0e761fb304705b0d…

MALICIOUS

PDF

43.5 KB Created: 2020-10-07 18:42:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: 7450fb022791bf6c771f840b134c4067 SHA-1: d14ac7dd9df6e30d528a417dfd32b3fa785cf2f8 SHA-256: 0e761fb304705b0d153bfd2ab19d0983d7f5236f0ecb262243765284a9dc5002
224 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, many pointing to external PDFs hosted on various domains, suggesting a link farm or redirection scheme. A critical heuristic identified a link to known malicious redirector infrastructure at https://cctraff.ru/strik?keyword=effective+javascript+pdf, which is the primary indicator of malicious intent. The ML classifier also strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 6

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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.
  • 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://cctraff.ru/strik?keyword=effective+javascript+pdf In PDF document text
    • http://kobiv.iparegion4.com/uploads/1/3/1/4/131482826/8828368.pdfIn PDF document text
    • http://fewesoj.4wardproject.com/uploads/1/3/2/3/132303099/lefuxebomizijo-rotagu-digalodajis.pdfIn PDF document text
    • http://tesamo.bowieknifestudios.com/uploads/1/3/1/1/131163729/1619607.pdfIn PDF document text
    • http://sebopenat.omninsw.waggamatters.com/uploads/1/3/1/8/131857120/zejenosatiza.pdfIn PDF document text
    • http://files.kpsm.net/uploads/1/3/1/6/131637362/5ea3f.pdfIn PDF document text
    • http://juxadebe.multifaithstorytellinginstitute.org/uploads/1/3/1/3/131380066/sebasawixe-lutilokew-levagonom-titejutawibini.pdfIn PDF document text
    • http://files.ktabkhaneh.com/uploads/1/3/0/8/130874143/07ea252003d0eb.pdfIn PDF document text
    • http://files.womenartistsreaction.com/uploads/1/3/2/3/132302863/8d22be5d98d153.pdfIn PDF document text
    • http://jenikek.eliteeuromotors.com/uploads/1/3/1/4/131409200/vigexugenu-gaxow-wojesove.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/dce6d34e-faaa-452e-90d8-c8c169025637/pojiduk.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f8604024-59e8-4637-9a42-92e30e7f7852/nisov.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7921db88-66bb-4cc0-9b4f-4acba71cba2b/donazijitukagadavutupim.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f55cf74b-f4e1-4f7c-b9cf-8e4a0e235f40/batavapurinekujimigimez.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6400b057-8cae-41fc-ac7d-c9f9796a8024/legef.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_off00006d30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x6D30 5208 bytes
SHA-256: a894ec3ee4f6057ebcf1c9e91f8b81f8d8e3ee517dafdeec30915b1b3c5bafaf
font_01_sfnt_off00007f08.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x7F08 10088 bytes
SHA-256: 7c8fa2819e7cbda0f31d41ec7580205dc6675489343a26dda9edb177984b88dc