Malicious PDF — malware analysis report

Static analysis result for SHA-256 4eceb4a9d7eacbad…

MALICIOUS

PDF

82.5 KB Created: 2021-03-28 00:47:30 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 7da2bd7e3e1f1be36afdc8f87f157124 SHA-1: 21db4525b66ebcf1759d107714a4975b0108aa60 SHA-256: 4eceb4a9d7eacbad45d5a8aafff67409415f2cfd0c7922a6cb65016ef9a63bc3
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. It contains a large number of external links, with one pointing to 'vilenefex.ru', suggesting a link farm or phishing attempt. The document body is heavily obfuscated and unreadable, but the presence of external links and the heuristic 'PDF_SEO_LINK_FARM' strongly indicate a malicious intent to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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/award?keyword=conical+intersection+pdf
    • https://cdn-cms.f-static.net/uploads/4366668/normal_6023b94327de3.pdf
    • https://static.s123-cdn-static.com/uploads/4375503/normal_6007aa89b0ba5.pdf
    • https://cdn.sqhk.co/rewazexi/wig60tQ/55585315178.pdf
    • https://static.s123-cdn-static.com/uploads/4382771/normal_5ffbcd544a243.pdf
    • https://cdn-cms.f-static.net/uploads/4476954/normal_6035b2cf52ca0.pdf
    • https://cdn.sqhk.co/suxidixip/ghUiShh/xanejizidom.pdf
    • https://cdn.sqhk.co/fenazijeguk/jdhjhcc/red_velvet_offline_kpop_wiki.pdf
    • https://cdn.sqhk.co/worijekegir/herihhb/8974364429.pdf
    • https://cdn.sqhk.co/lulufebexefe/eijgiij/97814560785.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/ee3dcf39-e538-4e22-9879-b26644e026f8/how_to_thread_a_old_singer_machine.pdf
    • https://s3.amazonaws.com/zubuwujoxom/drama_korea_brilliant_legacy_subtitle_indonesia.pdf
    • https://uploads.strikinglycdn.com/files/ccf4e5f5-1085-45ec-8696-76a333dce445/how_to_reset_income_tax_password_through_dsc.pdf
    • https://uploads.strikinglycdn.com/files/53a7474d-a0fe-4d91-b0bd-186c520b8f2d/nupabebuvabum.pdf
    • https://s3.amazonaws.com/lolaritemukole/sound_drivers_for_windows_7_64_bit_hp_pavilion_g6.pdf
    • https://9abff256-b119-4e75-a612-dfc075f5428e.filesusr.com/ugd/c73517_922af3881a064cc087d488f29ddf9325.pdf?index=true
    • https://uploads.strikinglycdn.com/files/5d2b4b93-9f45-4d1a-aa5d-ae7b992f6537/where_can_i_find_a_refrigerator_repairman.pdf
    • https://s3.amazonaws.com/jifedefujodu/8205810129.pdf
    • https://s3.amazonaws.com/wutogugej/walton_categories_of_art.pdf
    • https://uploads.strikinglycdn.com/files/80c24fa4-f601-4de3-878a-2934aad3d338/how_to_get_aircel_port_number_online.pdf
    • https://s3.amazonaws.com/mubefula/how_to_write_a_good_summary_4th_grade.pdf
    • https://uploads.strikinglycdn.com/files/da42db94-ad6d-403e-be48-555ca54da233/how_to_change_my_beats_ear_pads.pdf
    • https://uploads.strikinglycdn.com/files/c600d3df-0808-4d4c-88bb-1d91369fd63e/lean_mean_fat_grilling_machine_waffle_instructions.pdf
    • https://94aa8f26-b07a-4c24-bdb4-4112657565c9.filesusr.com/ugd/37428b_e7d30f2eae81427299bd4e77df69e1cb.pdf?index=true
    • https://uploads.strikinglycdn.com/files/a94c57dd-27b9-426b-bc82-8f194105da8d/55734038809.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001035b.bin
a549c600364e2e4169b9750286cd54071b7140a2706dc1223271890883eab271
pdf-font-stream PDF embedded font (sfnt) at offset 0x1035B 5052 bytes
font_01_sfnt_off00011497.bin
8cd94cf3b03e7e309292c7bb1cfa23d799cdbf5adc8447c2bda2cce6cf592113
pdf-font-stream PDF embedded font (sfnt) at offset 0x11497 11512 bytes