Malicious PDF — malware analysis report

Static analysis result for SHA-256 1d9fc04e298ec333…

MALICIOUS

PDF

77.1 KB Created: 2021-03-22 02:34:36 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-02
MD5: 4e26f87f9bd60b24e01270bc9dc488b0 SHA-1: 85e3d5168bd30415252f4c3188831696303b6c56 SHA-256: 1d9fc04e298ec3332207ed7df928a662766e9a6176e82e698f4b0afa5f626d1f
126 Risk Score

Malware Insights

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

The PDF file contains numerous embedded URLs, many of which point to disposable hosting and are flagged as link farms. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically identified as phishing or a trojan. The document body, though heavily obfuscated, suggests a lure related to educational content ('Cell structure and function answer key'), which is a common tactic for phishing or malware delivery via spearphishing attachments.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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/123?utm_term=cell+structure+and+function+answer+key PDF link annotation
    • http://bossyonlinex.com/zajovxtpwy.pdfIn PDF document text
    • http://tifeguga.22web.org/brand_awareness_book.pdfIn PDF document text
    • https://cdn.sqhk.co/kufagilan/igWxKgh/27543163734.pdfIn PDF document text
    • http://detonicro.website/beintehaa_serial_sad_songa3bwr.pdfIn PDF document text
    • https://cdn.sqhk.co/bisuligiga/i1ichbi/dikasusirufigibavipaza.pdfIn PDF document text
    • http://drnextact.xyz/hitachi_12_compound_miter_saw_c12fdh7m19o.pdfIn PDF document text
    • https://cdn.sqhk.co/dejuxafe/9Pep3jb/b_section_taper_lock_pulley.pdfIn PDF document text
    • https://cdn.sqhk.co/renosopezare/2NtQyid/fear_the_walking_dead_full_episodes_season_3.pdfIn PDF document text
    • http://reduslim-buy.site/end_of_the_world_lyrics_jojoux48z.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://gerufufa.epizy.com/82628341244.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6550aecb-07a3-4323-988f-5552d139d040/what_are_the_5_types_of_communication_as_listed_by_the_text.pdfIn PDF document text
    • https://s3.amazonaws.com/jamuluvuvava/fetenasaroteguliga.pdfIn PDF document text
    • https://s3.amazonaws.com/zoromexemuzid/59477793496.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/844a5eb5-c3c2-41f8-ae24-57bee9300948/forces_and_motion_basics_phet_simulation_lab_answer_key.pdfIn PDF document text
    • https://s3.amazonaws.com/mexesazaxasa/meketumomarotuvobegu.pdfIn PDF document text
    • https://s3.amazonaws.com/suzujewa/aviva_stakeholder_pension_funds_performance.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e4732ff6-cfc1-4240-9f71-6e519ebd18cb/glencoe_algebra_2_textbook_online.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c332d21e-2625-4ae7-ba6c-44ba103b05a1/10266998690.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/09eeeab3-a7f0-4212-bbc0-3af4cf5fd727/discrete_and_combinatorial_mathematics_fifth_edition.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5e9e6169-30e5-454a-83b7-dadad65d3bf4/buvedatiwovobusep.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/0e1b8ad1-dc17-473f-9672-c9f2f389c2d0/zofowojuzaxemekisawumen.pdfIn PDF document text
    • http://laxuwesesanaw.rf.gd/balivalinikosotaji.pdfIn PDF document text
    • http://dilabopitomosif.epizy.com/autosar_adaptive_platform_security.pdfIn PDF document text
    • https://s3.amazonaws.com/jajoxulabojaso/natelusifufuvekulurelipa.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_off0000f069.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF069 5176 bytes
SHA-256: f4645aff2f5a5c58434f55a33d970e178b853f29131acff6c6bae875bdb07deb
font_01_sfnt_off0001022d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1022D 10800 bytes
SHA-256: be5c3b6698a0e18e35932171f60f4fa50709d19ac00af1baba700a99761611e4