Malicious PDF — malware analysis report

Static analysis result for SHA-256 3424f34ebaaae3ee…

MALICIOUS

PDF

78.9 KB Created: 2021-05-30 02:43:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 121b746627ed3361a7bb5ecd81ad1e1f SHA-1: dd49d4c0550e0a84f46f5a04f9978279ac13402a SHA-256: 3424f34ebaaae3ee0b981e0b669b8e0e575dd91b79c0922cd62a03fa424d6388
186 Risk Score

Malware Insights

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

The PDF file contains a link farm designed to redirect users to various PDF downloads, masquerading as search results. The heuristic 'PDF_SEO_LINK_FARM' indicates a large number of external links, with one prominent URL being https://pelibifir.ru/strik?utm_term=encyclopedia+britannica+15th+edition+pdf+download. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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://pelibifir.ru/strik?utm_term=encyclopedia+britannica+15th+edition+pdf+download PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4421341/normal_5fc63bf281c6b.pdfIn PDF document text
    • https://sujoxiwu.weebly.com/uploads/1/3/4/8/134879933/karuwivodiwom.pdfIn PDF document text
    • https://dajurejew.weebly.com/uploads/1/3/4/7/134753869/3b80b2.pdfIn PDF document text
    • https://sibikobibe.weebly.com/uploads/1/3/4/0/134040949/zaxisev.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4413564/normal_60b26b7217db1.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4404124/normal_5fdb612a5d41a.pdfIn PDF document text
    • https://kibanelamuvudu.weebly.com/uploads/1/3/0/9/130969844/zoriwufagogules.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490739/normal_600cf6a527498.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4475725/normal_605f0b7594416.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4476445/normal_603d28875ca80.pdfIn PDF document text
    • https://lewofadexireg.weebly.com/uploads/1/3/4/8/134868993/05fa6ed.pdfIn PDF document text
    • https://puwibovur.weebly.com/uploads/1/3/4/6/134639487/mowenuruwo.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4415327/normal_6034408961894.pdfIn PDF document text
    • https://jomezafivawig.weebly.com/uploads/1/3/1/8/131856232/4554299.pdfIn PDF document text
    • https://pozetegafikule.weebly.com/uploads/1/3/4/8/134857311/9c160050.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413454/normal_602099b1b1879.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/319b6136-ec2c-42fe-8119-dc91f000e8b1/lanudakelip.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4bbdcf68-5f5a-47ab-a075-e821927852dd/how_to_restart_a_motorola_phone.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0ae515a2-e016-4cd3-9416-8796d9afffb0/25259915231.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6c8ac72b-71f6-4d40-8aef-d24e4a0bf94d/how_to_ace_competency_based_interviews.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/748df61a-c86d-4c98-9d73-8e49ca565aac/bozamenemi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/15750d71-5b29-4f49-b8f1-cb2c803da56b/three_pillars_of_zen_wikipedia.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d5cb77a7-180d-456a-8165-7bfe11098e54/50076133666.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6f2b8ad3-5c60-498d-bb77-2c74177b409d/how_to_write_a_letter_for_personal_religious_exemption_from_immunizations.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_off0000f234.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF234 5532 bytes
SHA-256: 89a0f3f502b0e370577fe2cc17b336c2e1b737cde1e1364e4644a78013a1e695
font_01_sfnt_off00010524.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10524 11996 bytes
SHA-256: 4862572463d28be383718e5bc9d471af79316b29e8d1601bd7f68a14413e1eda