Malicious PDF — malware analysis report

Static analysis result for SHA-256 65c4a33ae5a2a8a8…

MALICIOUS

PDF

77.3 KB Created: 2021-03-12 14:46:42 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: affa5af42e1d969cacf887703cebe816 SHA-1: b4bf023c211256e9a79b50614456e536d0655be1 SHA-256: 65c4a33ae5a2a8a862229d2960113f7f0c1c9a7c24325c416fd919549d0af166
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 hosting, suggesting a link farm or SEO manipulation tactic. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of malicious activity.

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://zajinet.ru/123?utm_term=ifrs+and+gaap+differences+in+balance+sheet PDF link annotation
    • https://cdn.sqhk.co/dekavaka/cBJjcib/fazerikasem.pdfIn PDF document text
    • https://cdn.sqhk.co/pasezateda/jjEgfUB/wecom_wechat_web.pdfIn PDF document text
    • https://cdn.sqhk.co/pejasibupap/iaigygf/capture_the_flag_book_summary.pdfIn PDF document text
    • https://cdn.sqhk.co/dakizenewa/bhfhaie/19349502629.pdfIn PDF document text
    • https://cdn.sqhk.co/bijukipuj/jijexje/vax_carpet_washer_black_friday_deals.pdfIn PDF document text
    • https://cdn.sqhk.co/pigevikuwi/adugdNq/bafaxoxefibemosij.pdfIn PDF document text
    • http://alisaborodaenko.design/the_lost_vikings_iiikvlc9.pdfIn PDF document text
    • http://ig-support-service.com/55494054414200wl.pdfIn PDF document text
    • https://cdn.sqhk.co/benanejufa/heKjbvk/sticker_zoned_meaning.pdfIn PDF document text
    • https://cdn.sqhk.co/boguzivipel/ecV179I/lightsaber_for_sale_ireland.pdfIn PDF document text
    • https://cdn.sqhk.co/rigidaluta/dhfgghj/hero_wars_mod_apk_android_1.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://61090d85-22e6-4724-b969-52a17785150c.filesusr.com/ugd/952c2e_d0982dbe97fe4ae89fa3eb3753a9a41c.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/b7c1601f-e791-46af-8fca-634245c42c87/92895252063.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/030dc3b4-0b7e-4cb6-94e9-cf6c9cb2f7d7/28464027538.pdfIn PDF document text
    • https://s3.amazonaws.com/gowupuzokowuxes/does_netflix_have_little_shop_of_horrors.pdfIn PDF document text
    • https://2aa89031-56ac-4de1-b828-aabe99840ec8.filesusr.com/ugd/cf14a4_8909846d5f1f4c22bd38b817bc17dd10.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/cf2fbe12-fd92-4341-bfff-96de0167c345/dremel_225-01_flex_shaft_attachment_with_multipro_keyless_chuck.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/dbd82ca4-0522-4244-ad6c-a51b492da828/stop_stealing_sheep.pdfIn PDF document text
    • https://6eed613e-cbae-405e-b458-9655ef9033f8.filesusr.com/ugd/e4f6f0_aa1d7e3c506044dbb3deca0495b86e59.pdf?index=trueIn PDF document text
    • https://52ed6390-a5c1-4502-9f93-599cf6d98ad1.filesusr.com/ugd/f7fbc8_ef2dfa55f9ce46088d6ce227bcdb6cd4.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/fffd30f0-6043-482a-8d21-f1e6c824b7b1/jlab_jbuds_charging_instructions.pdfIn PDF document text
    • https://535a9070-e28a-464b-adc5-c02ad08be00b.filesusr.com/ugd/9df9d6_11fc2141e9674e1db77b836c791e3c98.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/luropiw/which_branch_of_mba_is_good_for_mechanical_engineers.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_off0000f1f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1F7 5492 bytes
SHA-256: 791c2088df959579c9b9e29b2ac2b219378f2f0f7f93c5d934ba70821f9d4afb
font_01_sfnt_off00010495.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10495 10240 bytes
SHA-256: db08314979e12967187b5b94cd08c99a80f5a097ab8a955b108871b6e257691f