Malicious PDF — malware analysis report

Static analysis result for SHA-256 71b376cce8d5365a…

MALICIOUS

PDF

76.5 KB Created: 2021-03-23 01:52:08 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: 6e8ee5d0b09543a82f36c83a4ff42c88 SHA-1: 2f61c5537c747e70b280bdcf72e13bac2e5cb6d6 SHA-256: 71b376cce8d5365ab5dab788a15bd90c0f69aaf1c343eb464b729ead4a834642
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains a link farm with numerous external URLs, including one pointing to zajinet.ru, suggesting a phishing or malware distribution attempt. The PDF structure and embedded links are consistent with techniques used to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://zajinet.ru/strik?utm_term=how+to+install+a+shop+vacuum+system PDF link annotation
    • https://sutivekawexebe.weebly.com/uploads/1/3/1/6/131636655/bfff4e1b022.pdfIn PDF document text
    • http://zukesijinizik.mywebcommunity.org/kapawekamizigomanag.pdfIn PDF document text
    • https://vimedapajabapi.weebly.com/uploads/1/3/5/3/135309909/5758259.pdfIn PDF document text
    • https://silorofolukut.weebly.com/uploads/1/3/4/2/134265947/8583605.pdfIn PDF document text
    • http://palubofapejuraw.mywebcommunity.org/pasexaxobokujajerinef.pdfIn PDF document text
    • https://sisilodoja.weebly.com/uploads/1/3/1/4/131406442/mazogefotowe.pdfIn PDF document text
    • http://gebevojika.mygamesonline.org/the_signalman_audiobook.pdfIn PDF document text
    • https://dolojimopa.weebly.com/uploads/1/3/4/8/134887070/piresuferesol-vapeben-xugoguv-mofubuzarigo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://e3055f73-6236-423b-b810-4bc1a15f300f.filesusr.com/ugd/fa12d1_fda25cc3766446a99478a10c94d9fe0a.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/21e2688e-d493-4f78-aeee-1fa2ce338aed/stock_investing_for_dummies_drive.pdfIn PDF document text
    • https://49b821e7-ee7e-41b4-809b-d0417b8c1ddf.filesusr.com/ugd/927743_c62e142c2d704b7abd8d85252149da35.pdf?index=trueIn PDF document text
    • https://27420876-d215-4860-9a72-f48db0d0c320.filesusr.com/ugd/4062c2_60738adaad894adea166215806d0f725.pdf?index=trueIn PDF document text
    • http://kanuximus.rf.gd/converting_litres_to_ml_worksheet_ks2.pdfIn PDF document text
    • http://sasejas.epizy.com/types_of_screws_and_bolts.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d316d33f-aa9e-430f-9035-8a3d6d4dd600/how_to_fix_slow_download_speed_on_blizzard.pdfIn PDF document text
    • https://09d7e2b9-79a3-4876-9e00-73a1ba4263a4.filesusr.com/ugd/92fcd7_5c94fb96e9b244f4b4b5676b7bd6a1ea.pdf?index=trueIn PDF document text
    • https://5366dd3f-28a3-4342-b8e5-5bed86455aec.filesusr.com/ugd/a92322_8b1db6cab81e4fc58d809c87f13b954d.pdf?index=trueIn PDF document text
    • https://6e37e838-c278-4d46-baa9-25b8497af200.filesusr.com/ugd/fbcb80_08cc8b9aa2344f5b829500de9828294c.pdf?index=trueIn PDF document text
    • https://6b137298-3864-41c5-aaa3-11744000c3c2.filesusr.com/ugd/b916f4_9deb4897b9084292bfc8b1657eccc253.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_off0000ec22.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC22 5292 bytes
SHA-256: bc51d2782201c527eb3a18c1ef73e3f9e17b0fafa3c722ae466581ce444d8b62
font_01_sfnt_off0000fe19.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE19 10820 bytes
SHA-256: 09eb158c2723220290e53c4370020708bf756ccad343a72702b71b1bf17a0a12