Malicious PDF — malware analysis report

Static analysis result for SHA-256 cf5473e73ff889a6…

MALICIOUS

PDF

81.5 KB Created: 2021-03-19 18:48:26 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-07
MD5: b6a18b31986753b37ca98760743058e9 SHA-1: 01f56bb0ec65352bbf168c6b70703c4806eb5933 SHA-256: cf5473e73ff889a633dd64c98781d30e6fc3f504ba7e64d14e0651eaf2e6ff8b
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, indicating a link farm or SEO spam campaign. The ClamAV detection and ML classifier strongly suggest malicious intent, likely to redirect users to phishing or malware sites. While no scripts were explicitly extracted, the PDF structure and heuristics point towards malicious redirection as the primary attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://vilenefex.ru/wix?keyword=little+annie+fanny+comic+read+online PDF link annotation
    • https://ragulifogikub.weebly.com/uploads/1/3/3/9/133986704/wuvokeriz_pujixixevege.pdfIn PDF document text
    • https://xonasuxodu.weebly.com/uploads/1/3/2/6/132681295/guvuxexarisugi.pdfIn PDF document text
    • https://fuwamelewupo.weebly.com/uploads/1/3/4/1/134131589/buzoliro-denilel-tovubidowapolin-xivanumure.pdfIn PDF document text
    • https://tuboxivodase.weebly.com/uploads/1/3/4/3/134387713/3aed68388c444d.pdfIn PDF document text
    • https://dupazenulejafu.weebly.com/uploads/1/3/4/3/134331878/1590828.pdfIn PDF document text
    • https://ninalekenapuboz.weebly.com/uploads/1/3/4/0/134017067/33ba260ae.pdfIn PDF document text
    • https://gaxiliwila.weebly.com/uploads/1/3/1/3/131383945/4f8dd213d111.pdfIn PDF document text
    • https://rajiketuwomap.weebly.com/uploads/1/3/5/9/135957261/43edcbfd7f167.pdfIn PDF document text
    • https://rodekovolopipek.weebly.com/uploads/1/3/4/3/134372516/tenixuwigibe.pdfIn PDF document text
    • https://palogipotutaz.weebly.com/uploads/1/3/2/8/132814365/88449.pdfIn PDF document text
    • https://gixujadimi.weebly.com/uploads/1/3/4/7/134708567/881981.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://ebd73b9a-b255-48a5-b781-2bd84b483b4c.filesusr.com/ugd/956c05_1a9b2da1f05f4e189aa516aba3f14710.pdf?index=trueIn PDF document text
    • https://5a1138df-423b-4a5d-a7c7-36223740754e.filesusr.com/ugd/a72fa8_9cd1455e58d84dc38b27e5574def7eeb.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/10da12f0-8f4a-4644-80aa-1387a842fb28/funniest_pet_rock_memes.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/87d70e9b-8e27-4a40-b213-a213e79ef73c/asm_handbook_vol_18.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5c8eb515-9cbc-4663-9367-63f4c5af7f25/57824333069.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1c0af73e-8d03-4652-9e90-9bd5dd24182a/how_to_become_a_peds_nurse.pdfIn PDF document text
    • https://506dbbd1-d4b3-44b1-a4c9-6b5d0cab6a23.filesusr.com/ugd/c75f60_e7acb108c1264b6b8dd885ff3946bc0a.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/4bc52bf3-6441-4dd6-9baf-64e6bd05d545/muwevisomibax.pdfIn PDF document text
    • https://cad90261-f038-4e8a-b384-2e0e37e6cb8c.filesusr.com/ugd/4c4e45_f79a4b5ec04d4b968f21fbf47a92bce5.pdf?index=trueIn PDF document text
    • https://71f68c9c-1037-483c-a0ca-f268b7ddd3c8.filesusr.com/ugd/87fdc7_f14d0f683af14b3d9f1c287cfe42ec54.pdf?index=trueIn PDF document text
    • https://03386fec-e341-46be-bf9f-2f2bd19f9bfe.filesusr.com/ugd/bf57b5_32f0030f1b03424fb65d127511ee4cbb.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_off00010180.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10180 5032 bytes
SHA-256: 40d1e8cbf0c19cd640b338b56a678fdd1d0bd6d5f75f68801d1149dfdffc3995
font_01_sfnt_off00011297.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11297 10632 bytes
SHA-256: e54dbba8a96f17fa693a18e8a7d6c79e02a70738f104e912b02a241be0218b09