Malicious PDF — malware analysis report

Static analysis result for SHA-256 40c5aa2a387004dc…

MALICIOUS

PDF

81.8 KB Created: 2021-05-28 13:01:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: 076139213d00ec19add385207a777b32 SHA-1: 1ac6d2682098ae341ee7f4dff5e830ecd140c750 SHA-256: 40c5aa2a387004dc6cd19b99c4d4da4a887120c5df67edc0c0659a16a777f8b5
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 0.9994

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://midufefew.ru/strik?utm_term=complete+the+sentences+with+the+present+perfect+or+past+simple+from+of+the+verbs+in+brackets PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4376866/normal_6055824e0c57b.pdfIn PDF document text
    • https://pogedefulelot.weebly.com/uploads/1/3/4/6/134628496/funijulupezenote.pdfIn PDF document text
    • https://voledepegos.weebly.com/uploads/1/3/1/4/131407008/3976407.pdfIn PDF document text
    • https://kosukanawator.weebly.com/uploads/1/3/5/3/135304621/zowuxet.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4427080/normal_601104ded053f.pdfIn PDF document text
    • https://bewarovawizijus.weebly.com/uploads/1/3/4/4/134454629/6766870.pdfIn PDF document text
    • https://nefopebawobujo.weebly.com/uploads/1/3/4/3/134380481/5693641.pdfIn PDF document text
    • https://kutufesivom.weebly.com/uploads/1/3/4/6/134632784/9f0e32d4c7c77.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4460677/normal_600d3925a805d.pdfIn PDF document text
    • https://lonojoxojiliw.weebly.com/uploads/1/3/1/4/131438577/8a4d3736495.pdfIn PDF document text
    • https://tupirusu.weebly.com/uploads/1/3/4/7/134702138/reparuwosowupe.pdfIn PDF document text
    • https://rilitovewub.weebly.com/uploads/1/3/4/0/134095842/firikepazubabuv.pdfIn PDF document text
    • https://sozivutapadonen.weebly.com/uploads/1/3/1/1/131164462/5474575.pdfIn PDF document text
    • https://rezojitelato.weebly.com/uploads/1/3/4/6/134649293/5095122.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4423154/normal_60699e8cdde9c.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4489588/normal_5feb9b9976b52.pdfIn PDF document text
    • https://fuvutefimege.weebly.com/uploads/1/3/1/4/131453053/sanilazir.pdfIn PDF document text
    • https://zajevikafe.weebly.com/uploads/1/3/5/2/135297545/1002512.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/00184715-f00c-4263-9f20-452325294369/29856738709.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b6cb95e8-38d7-4eaa-94b1-6473078406f3/2014_ford_mustang_gt_for_sale_san_antonio.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/508a9451-9d0e-4a5b-9e13-7bff5e74326a/mofemitixefe.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/775e75b8-e6b6-4a83-be67-9c29215580ea/gujubapekovobexujujizon.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cc2a622f-fe8c-44f9-bc26-5db74afac0dd/what_hydraulic_fluid_to_use_in_a_log_splitter.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_off000101ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101AC 5516 bytes
SHA-256: f46d96d6a8b97bfb29a75c87b88733c5834e42210dac7b7d3174da2f85feb1f7
font_01_sfnt_off00011457.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11457 10740 bytes
SHA-256: cf91bc1cc5646b90a8c1bab8c6805171f1dc8901e5844bfc9b7359fa45b81fc7