Malicious PDF — malware analysis report

Static analysis result for SHA-256 9c38c58bf2e43c4f…

MALICIOUS

PDF

78.8 KB Created: 2021-05-09 14:54:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: a62eb9b95ff2732cb20a60d4abd139da SHA-1: a687f818d8131481ccec9ef7396146c99e8c3059 SHA-256: 9c38c58bf2e43c4f72cab39b81d3fd4ca9208212602e78b047f3c7551adb1b04
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 pointing to disposable domains, suggesting a link farm or SEO poisoning tactic. The primary URL, https://vilenefex.ru/strik?utm_term=maths+word+problems+for+grade+4+division, is likely a lure to a malicious site. ClamAV and ML classifiers also flagged this PDF as malicious, indicating it's likely a phishing or malware distribution document.

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=maths+word+problems+for+grade+4+division PDF link annotation
    • https://gobodukigibab.weebly.com/uploads/1/3/1/8/131856162/26afe2d.pdfIn PDF document text
    • https://dozolujikofirig.weebly.com/uploads/1/3/1/8/131856703/9505664.pdfIn PDF document text
    • https://ribavazo.weebly.com/uploads/1/3/5/3/135322422/wedanidemedexu_mopegirifu_viguwabi_kulipepasawuduz.pdfIn PDF document text
    • http://ruwozapezorirar.iblogger.org/what_is_the_meaning_of_christmas.pdfIn PDF document text
    • http://buluzapigal.22web.org/xexemaxigenukizigutovefaf.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/zafijukopa/vekeramapasi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cdea9768-973e-4203-9621-72b1ecff1f56/life_operating_grant.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a874d8aa-15e1-420d-bbdd-9d27031ab426/88845393116.pdfIn PDF document text
    • http://raxusitusumulag.rf.gd/79164178533.pdfIn PDF document text
    • https://s3.amazonaws.com/dugibabafod/ritokebalixutini.pdfIn PDF document text
    • https://s3.amazonaws.com/tazopaju/tulaf.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/54a18fbd-ae89-4def-bbaa-97e33781c138/ridgid_10_inch_miter_saw_review.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1c807b22-08e7-4b20-a9cb-2f9ccccff153/gaussian_elimination_questions_and_answers.pdfIn PDF document text
    • https://s3.amazonaws.com/mulerux/clinical_data_management_salary_in_india_for_freshers.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4eddf06b-fe3f-418e-859c-b67930aa3344/12395923269.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d3901c06-2d3b-4891-a202-7454a3e67421/18669698299.pdfIn PDF document text
    • http://gubawakelu.onlinewebshop.net/descent_into_avernus.pdfIn PDF document text
    • http://robowogutalopet.epizy.com/17580273898.pdfIn PDF document text
    • http://wafeginake.rf.gd/18583447005.pdfIn PDF document text
    • http://goxafebo.myartsonline.com/ocean_acidification_causes.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/385d96d1-1d35-49ad-8da0-ec333cf63e2f/libro_el_caballo_de_troya_1.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_off0000f5b2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5B2 5840 bytes
SHA-256: 35c28fa9b118604ee11bf1057660a0a3cd6c867a63299442cd3703d242aaf332
font_01_sfnt_off0001098e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1098E 10492 bytes
SHA-256: 153ebfe1ad9e3ee28a0f2dda40a0dac4b07f79c890608fe7e63bb0d8a76dbfc5