Malicious PDF — malware analysis report

Static analysis result for SHA-256 921370f5c869ca0b…

MALICIOUS

PDF

84.0 KB Created: 2021-03-09 02:55:46 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c66e4f4a2136aaaba819961a2a3ef6b8 SHA-1: 42a7d5201069ef7da5c462c27795adff4d6514db SHA-256: 921370f5c869ca0b966022db7acbe2f4b2d9317ee779634005df8a210e7aae00
164 Risk Score

Malware Insights

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

The PDF file contains a heuristic firing for PDF_SEO_LINK_FARM, indicating it's part of a link farm designed to attract users searching for specific content like 'case files neurology pdf free download'. The presence of an external URI and a ML classifier flagging it as malicious further supports this. ClamAV also detected it as Pdf.Phishing.Trojan, suggesting a phishing or trojan distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

Heuristics 6

  • 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
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://midufefew.ru/award?keyword=case+files+neurology+pdf+free+download
    • https://cdn-cms.f-static.net/uploads/4389824/normal_603911b453b8f.pdf
    • https://cdn.sqhk.co/rufadexu/lX6iaI6/guess_the_actor_game.pdf
    • https://cdn-cms.f-static.net/uploads/4426410/normal_603c86156aabb.pdf
    • https://cdn.sqhk.co/bisadidizi/Ahgiakz/lifecubby_classroom_app.pdf
    • https://cdn-cms.f-static.net/uploads/4412895/normal_6038355348f8c.pdf
    • https://cdn.sqhk.co/vujejanar/gdf7pSk/baby_lyrics_song_by_joeboy.pdf
    • https://cdn.sqhk.co/mudemodox/gemGCXi/93146911960.pdf
    • https://cdn.sqhk.co/gudijupimeb/8bkhghR/bimevonaja.pdf
    • https://cdn.sqhk.co/miropefaneka/G0rgi11/learn_spanish_free_online_audio_lessons.pdf
    • https://cdn.sqhk.co/xunixenovapi/MKib9s2/tobinibawi.pdf
    • https://cdn.sqhk.co/rabuvimi/hLnhg23/pulsar_dual_fuel_generator_home_depot.pdf
    • https://cdn.sqhk.co/talokelom/giFngit/tutorial_de_comic_life_3.pdf
    • https://cdn-cms.f-static.net/uploads/4379987/normal_60126e9f496ff.pdf
    • https://cdn-cms.f-static.net/uploads/4378619/normal_6033c3d202089.pdf
    • https://cdn.sqhk.co/riwajamugem/iafnphf/double_dragon_trilogy_apk_data_mod.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://24a70dd4-b549-4b9e-9c0a-6eea45ab85ad.filesusr.com/ugd/ab0c63_2091c3fa38944190bc691d61f6eeb08a.pdf?index=true
    • https://35e1cc1d-5f6c-4a41-9b1b-b9ae8dddc97a.filesusr.com/ugd/351eee_e48fa167785342b88d4fbd054fce7a4d.pdf?index=true
    • https://s3.amazonaws.com/ravuxudibure/23824441099.pdf
    • https://s3.amazonaws.com/bezegoluzose/22965332416.pdf
    • https://40e214c1-1950-44e8-a195-e2c6eeb23253.filesusr.com/ugd/a517f4_f181dd8126774c8ca5ef8c0c796926fc.pdf?index=true
    • https://s3.amazonaws.com/sivanira/70704294243.pdf
    • https://41be308f-8a64-4dec-8b30-4937605be974.filesusr.com/ugd/f042fe_926e66fa494c4f0db344743687fd483f.pdf?index=true
    • https://700ceb37-22d2-47c5-9888-d858af679aee.filesusr.com/ugd/c345b0_aa4252a9d6834b2182b1f1bbacd7dbd6.pdf?index=true
    • https://s3.amazonaws.com/fasudikek/fish_culture_project_report.pdf
    • https://s3.amazonaws.com/rujimidujek/nuzekagifedajonipidipina.pdf
    • https://a540aa65-2eb1-4ac3-86d0-bf6a54daac96.filesusr.com/ugd/2d797c_eee0eb0b2f454df5b66b8f17b17a90c6.pdf?index=true
    • https://28546a20-d0cc-4b82-bb4f-6711990cd5a3.filesusr.com/ugd/0bcf16_2cc5ec7956e94c519bc5f7ec07d4182c.pdf?index=true
    • https://b3709dad-42f4-4621-9b7e-74d31ca978cd.filesusr.com/ugd/f91cf1_5a8c7fd3ae6d446586db38c5a778cfdf.pdf?index=true
    • 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
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f55c.bin
b0adf7fa6209925e977559ca1a8528c1dcf66cc2e465b2c15788af40fa1a4b44
pdf-font-stream PDF embedded font (sfnt) at offset 0xF55C 5308 bytes
font_01_sfnt_off0001078d.bin
001816c741e4eccf7e7058ae90215fb145d2a20054776b8a1a1377913b44a693
pdf-font-stream PDF embedded font (sfnt) at offset 0x1078D 10800 bytes
font_02_sfnt_off00012cb6.bin
a2ae3ae010fc9d233b854917841a89f72dd7fdf4cd45890bb076eddb464b4872
pdf-font-stream PDF embedded font (sfnt) at offset 0x12CB6 16104 bytes