Malicious PDF — malware analysis report

Static analysis result for SHA-256 645ab020c3b7e64f…

MALICIOUS

PDF

74.3 KB Created: 2021-03-22 00:20:54 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: 808a2db14dfe9254182ac6ae6fa35b96 SHA-1: 70170b9bc07206fd880d4fc2868dc7e010896334 SHA-256: 645ab020c3b7e64f8b717a4b8dd054c8361daddd594fe3b2ddc274b812eb66bd
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://vilenefex.ru/strik?utm_term=hewlett+packard+photosmart+5520+drivers PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4382407/normal_6030ea44cb3cf.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4481830/normal_60403d591c31b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4488572/normal_602a2418e700c.pdfIn PDF document text
    • https://raxopukefafifi.weebly.com/uploads/1/3/2/6/132695755/800361.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403271/normal_6021168223874.pdfIn PDF document text
    • https://jatitebomotopoz.weebly.com/uploads/1/3/0/7/130776336/d18031c16aea.pdfIn PDF document text
    • https://dabomisefeb.weebly.com/uploads/1/3/0/7/130775205/33960ac30793e6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4424991/normal_5fe9da77d5aaf.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4461497/normal_5ff4eb43e8f4c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4412575/normal_602523b101ecb.pdfIn PDF document text
    • https://saxexowiki.weebly.com/uploads/1/3/0/9/130969873/c7b4c48a3.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4477873/normal_5fedcbad63a63.pdfIn PDF document text
    • https://kiwiwutirove.weebly.com/uploads/1/3/4/7/134707888/beret.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4418963/normal_5ff9fe9a1e7f9.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4459319/normal_5ff06d172cb6a.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://9d1e48ad-bcd7-4831-9b7b-7108443a63b6.filesusr.com/ugd/136d07_4731d7e6dc3b499ba38bfe61ed5599d2.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/0651f87b-ffd8-4aa1-aead-6f00ae87d93a/fitbit_flex_2_price_australia.pdfIn PDF document text
    • https://d56a38bf-d62e-453c-9b5b-5b2fe88aea46.filesusr.com/ugd/359e64_f101828bcdc147d38ea9d06a7642f50d.pdf?index=trueIn PDF document text
    • https://6bc61794-ec17-45f1-96eb-8bed4cd57308.filesusr.com/ugd/217b8a_99b9b8ee719f46f5afc3eb0697445b44.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/d70ad0de-8091-4496-bc87-a66ee72c6dc8/64532381362.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c79a43c9-a7bd-43bd-aadc-4e78451fe046/wiselini.pdfIn PDF document text
    • https://00407fa8-a9ef-4b78-9bbe-46147fc8acf6.filesusr.com/ugd/5ecadc_a5720fb76cab44c2883482c3cb5c3aff.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_off0000e133.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE133 5888 bytes
SHA-256: 9dd317a57a67ad5dede6d2302bbd053e709c5b6c546d83b11890eb36a4298d30
font_01_sfnt_off0000f533.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF533 10816 bytes
SHA-256: 2391e7006bec55d77abefdbf991e8d4b24af1011cc78efe7f203019ed1d13c61