Malicious PDF — malware analysis report

Static analysis result for SHA-256 65926a20c3807767…

MALICIOUS

PDF

81.0 KB Created: 2021-05-20 23:55:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 9931d440836714ec70f00d1a827c2f92 SHA-1: 2bf2122f491e438129205897f00beaaed5b2fde3 SHA-256: 65926a20c380776772476afb41a14904160b825e330f2611f1287967cd168896
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links pointing to other PDF documents hosted on various domains, many of which appear to be disposable or used for link farming. This behavior is indicative of SEO manipulation or a phishing campaign designed to redirect users to malicious content. The ClamAV detection and ML classifier further support the malicious nature of this file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9994

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://zajinet.ru/strik?utm_term=michelin+guide+uk+2020 PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4391024/normal_5fda860fa4f64.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4488316/normal_5fca78cfbf2ce.pdfIn PDF document text
    • https://xobojurum.weebly.com/uploads/1/3/4/5/134599739/3223185.pdfIn PDF document text
    • https://fitokuzigijot.weebly.com/uploads/1/3/4/6/134681543/923e380d3d.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4477373/normal_605274ee508db.pdfIn PDF document text
    • https://kemigaguni.weebly.com/uploads/1/3/1/0/131070112/fulebefabigowuzenor.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4382423/normal_605d853c83d51.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4501361/normal_60688af20bd73.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4462736/normal_60232be832e72.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4492536/normal_602e28dc40700.pdfIn PDF document text
    • https://dotowukigirer.weebly.com/uploads/1/3/1/1/131163902/ganaxonavapox-pomarodak-dazulenuj.pdfIn PDF document text
    • https://pefopurez.weebly.com/uploads/1/3/4/3/134375846/lugav-moxezapunu.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4446633/normal_60011e0f974ff.pdfIn PDF document text
    • https://tozubovudifudi.weebly.com/uploads/1/3/5/9/135973827/2598940.pdfIn PDF document text
    • https://mufaguzesevulet.weebly.com/uploads/1/3/2/8/132814956/8762870.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4402717/normal_5fee679277f8f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490930/normal_603d665323621.pdfIn PDF document text
    • https://rufuroborotefin.weebly.com/uploads/1/3/1/8/131856068/3aef08b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415935/normal_602712a485226.pdfIn PDF document text
    • https://zuxevuzefadum.weebly.com/uploads/1/3/0/7/130775429/tisufegumepokapar.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/f911d107-fd3d-40ee-8c7c-c033c21df60d/34601134971.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/36a5a91a-02af-4468-bee9-6dc453cd387c/23047586195.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8e1fac70-7165-4ca0-8d1d-0a9b6ad6c275/flipaclip_unlocker_ios_free_download.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_off0000ff71.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF71 5060 bytes
SHA-256: 65104d8d75d2abd15968d454c48077ae406e741ad4a5aef2cb6030fea11339c4
font_01_sfnt_off000110bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x110BC 11604 bytes
SHA-256: 07d0acabec5d6aca1b66f21eeabee6b1880f8b65cec08a93e451151a2820ca92