Malicious PDF — malware analysis report

Static analysis result for SHA-256 23648d15bd34913b…

MALICIOUS

PDF

85.5 KB Created: 2021-03-19 20:59:53 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: 5c4112f49541fb41db4b40350a95175f SHA-1: 9f6d78c83ad215f684094c5ab93713e4abe44f39 SHA-256: 23648d15bd34913b6c9991cf89f293da1e3d8263a30fc8b36e722924bef881ce
186 Risk Score

Malware Insights

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

The PDF document contains a large number of external links, many pointing to disposable domains, indicating a link farm or SEO spam operation. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the PDF structure itself is designed to redirect users to potentially harmful external URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://soxebez.ru/123?utm_term=reject+application+email+template PDF link annotation
    • http://nurokojo.mypressonline.com/53241781039.pdfIn PDF document text
    • http://pixunune.sportsontheweb.net/good_quotes_from_alice_in_wonderland.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4462980/normal_602774d2c2fbd.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4366311/normal_60058ff799aa7.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4385633/normal_5fcc6acd48b5e.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/1c86742e-f7d9-4b22-a83f-226378265a68/45834787991.pdfIn PDF document text
    • https://5071cc05-3fa2-46b1-b944-d2523ca4b51d.filesusr.com/ugd/62e2c1_194fc7cbb16849ef8086382523a25f7e.pdf?index=trueIn PDF document text
    • https://ebbb41b5-b8b7-4bfc-9e1b-23e79ad93844.filesusr.com/ugd/5eba67_76836eff95394bf29ef6d1bb57964b15.pdf?index=trueIn PDF document text
    • https://2ddc7431-ff91-46e9-9708-195efd6cc195.filesusr.com/ugd/ffe0d3_7397021af75d4bcd9b5c420c1cf4f6fd.pdf?index=trueIn PDF document text
    • https://c0cead0d-5248-483d-940e-95cc3acd9bde.filesusr.com/ugd/20d83a_2281574509744434bcd20dcfa402ad4a.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/1cd110e1-e356-452c-bf8b-dda543ca449e/whats_another_word_for_clearly_stated.pdfIn PDF document text
    • https://18e99e0c-7034-4a8c-9069-267580a295b8.filesusr.com/ugd/b337f5_0f8b5c66cda745619b44644250a527f4.pdf?index=trueIn PDF document text
    • https://8458b573-1d6d-478c-912c-b10a972f31df.filesusr.com/ugd/150112_13cd7b9201e44afc943f061940bf520d.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/99bcec83-30f3-47e1-86a2-a1fad27c37ca/93090788143.pdfIn PDF document text
    • https://75a697d3-84f0-44cf-bab9-f05e37020c50.filesusr.com/ugd/7c3584_12e79d610dd247c1a55e9c2d7f0db86a.pdf?index=trueIn PDF document text
    • https://8e12fe21-47c1-448c-af9e-883e7c84523b.filesusr.com/ugd/52ac5e_3e77fb6b56bb46d18f88c5ec257f74de.pdf?index=trueIn PDF document text
    • http://nozozuwovore.atwebpages.com/do_lara_jean_and_peter_stay_together_after_college.pdfIn PDF document text
    • https://4e4301d6-cc9a-4939-960a-6b497c1efea6.filesusr.com/ugd/d78803_e97dbf1cddac4ad4863fa20576a2fedc.pdf?index=trueIn PDF document text
    • https://33c7e2ec-32fc-4676-a642-9d95a4379e01.filesusr.com/ugd/622218_93abf423917d4674905438a51c70a1da.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/539915c6-04fa-469a-b844-17335d9e2ba9/what_are_the_main_principles_of_teaching_english_as_a_second_language.pdfIn PDF document text
    • https://1e16f6d7-285b-4488-bf07-d3e24ac90e20.filesusr.com/ugd/417718_2b2e2d28e28e4eedaf31b0b2837de03d.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/40d9a55e-c85b-4887-b7b2-bafa6ecd02e0/jigevizexukopediradilab.pdfIn PDF document text
    • https://973697ad-ffa4-4f9d-85cd-0c9d1ea039ee.filesusr.com/ugd/5f5755_1a8613683a414bc9a7701f091a9dbc24.pdf?index=trueIn PDF document text
    • https://229c3593-bb94-4e5d-9b9f-ca3747df48ef.filesusr.com/ugd/145364_e7fc6ed357684550ae01066ac26cf457.pdf?index=trueIn PDF document text
    • https://891dfe3a-8969-4df2-b253-5ccc4ebbb7a0.filesusr.com/ugd/e66789_3e72feea6bd240d3bad142d0db1a2daf.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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_005_off00012de2.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x12DE2 17416 bytes
SHA-256: 336246c0be6f37bb78d364fb444b1769a4d3cbfc0a854a95a5e9c107f78d230c
font_00_sfnt_off0000f3bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3BB 4888 bytes
SHA-256: a472ff3f3057798f960eb2aa0c17d075ec983c117d3662f0ca5b1362c7e49e2a
font_01_sfnt_off0001045b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1045B 12712 bytes
SHA-256: deae555ae1c809fc1b0464faccaef7f69d9dec5d8ae07870224db8f7b0ddcb96