Malicious PDF — malware analysis report

Static analysis result for SHA-256 866d1856bb57bf4a…

MALICIOUS

PDF

77.3 KB Created: 2021-04-25 11:32:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-22
MD5: bef2e54a64a4be69f06a7d277cc9a5d5 SHA-1: 710587d28db622f949dc04493064d87cd41807e3 SHA-256: 866d1856bb57bf4a5e93a27809fddf9a3c2884a43ebbe810461c20151d01a331
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 0.9993

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=how+long+do+rheem+tankless+water+heaters+last PDF link annotation
    • https://cdn.sqhk.co/duwenaxiseve/ioI6yia/advanced_space_flight.pdfIn PDF document text
    • https://giwelexe.weebly.com/uploads/1/3/0/8/130814055/rufusejawibafogo.pdfIn PDF document text
    • http://puwufonizezez.22web.org/46697436392.pdfIn PDF document text
    • https://cdn.sqhk.co/nejibija/Lgj45jc/tv_series_pub_quiz_questions.pdfIn PDF document text
    • https://cdn.sqhk.co/lexelinowe/hjtghqL/tisidagunixoluzama.pdfIn PDF document text
    • https://cdn.sqhk.co/jabisopomuxo/jcvCaji/41809164302.pdfIn PDF document text
    • https://zapowiwowo.weebly.com/uploads/1/3/0/7/130776131/zepatawizetawixu.pdfIn PDF document text
    • https://cdn.sqhk.co/vixawutozama/0jdicig/newegg_return_policy_on_refurbished_items.pdfIn PDF document text
    • http://timedezalug.iblogger.org/monopolies_and_restrictive_trade_practices_act.pdfIn PDF document text
    • https://juporolo.weebly.com/uploads/1/3/1/3/131380745/xobudutodisasi_pekodofaruwaxet.pdfIn PDF document text
    • https://duweliga.weebly.com/uploads/1/3/4/5/134593675/sidusugukavon.pdfIn PDF document text
    • http://mezoterilijixa.22web.org/the_secret_dare_to_dream_ost.pdfIn PDF document text
    • https://cdn.sqhk.co/fukonovum/fjjhc8o/79372967699.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/bc33f221-9299-442c-bcff-0196529aa3e7/holmes_tower_fan_stopped_oscillating.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/640d2af5-d790-411e-a96a-e8d5ba9e249a/kejolupinapatud.pdfIn PDF document text
    • https://s3.amazonaws.com/sixolose/acomea_performance_a1_pt.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/09fa9adf-cfc8-4ed7-8f6a-af9f5ecc1076/38300148222.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/98f10644-382e-4b6c-845a-029d80a6a123/dudixekatenosokulen.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/98278e83-ad5f-4aaa-8a4b-f6e6c9aee7d7/how_long_can_you_store_a_green_smoothie_in_the_fridge.pdfIn PDF document text
    • https://s3.amazonaws.com/kiremefegonar/a1c_conversion_table.pdfIn PDF document text
    • https://s3.amazonaws.com/folexapurilowe/dapagemikunirivazobosuwe.pdfIn PDF document text
    • https://s3.amazonaws.com/boduxatavepe/online_admission_form_for_du_sol.pdfIn PDF document text
    • http://zotomogizolelaz.rf.gd/dubozoxufijaf.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_off0000efa1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFA1 5356 bytes
SHA-256: f906d38f2c1ddbbb25a0ca5d5a3aa1fa3717c2c54a518718c77084aa815b52c0
font_01_sfnt_off000101b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x101B8 11136 bytes
SHA-256: 3034e7a048a4abcf7f6d9406e184caddd3fcb684d264b8ceee29fd94a55b2c58