Malicious PDF — malware analysis report

Static analysis result for SHA-256 c556f2509649bf76…

MALICIOUS

PDF

75.0 KB Created: 2021-04-08 19:59:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e9ba19b7e174be8f1234d55dc1b58db6 SHA-1: bd83d579f7e20e5cf0f1bd7afaf81cc18d523267 SHA-256: c556f2509649bf76284995751c4509c5d38c593ea8a97f680da6c044f20ac844
186 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics, including a critical ClamAV detection for 'Pdf.Phishing.Trojan'. It contains a large number of external links, many pointing to disposable domains, suggesting a link farm designed to distribute malicious content or conduct phishing. The document body, though partially corrupted, contains text related to an 'Examen diagnostico' which serves as a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://zajinet.ru/strik?utm_term=examen+diagnostico+historia+universal+segundo+secundaria+pdf
    • https://cdn.sqhk.co/pinofizulag/diitgix/32433163944.pdf
    • https://cdn.sqhk.co/jebuxanit/ndHVTfs/fizidutivuzikuluvabitet.pdf
    • http://kupiokno.su/somojolopexotijapija1kyqb.pdf
    • http://summerita.fun/36457894679p6una.pdf
    • https://cdn.sqhk.co/wojipezusax/70himeW/amtrak_schedule_san_antonio_to_alpine.pdf
    • http://ogranicbio.fun/96355299974snwkr.pdf
    • https://cdn.sqhk.co/dijobika/Ukijifu/59008766487.pdf
    • http://omoikiri.info/que_significa_la_palabra_licita_en_la_biblia_arras8inbh.pdf
    • http://chebsvet.ru/mulevofepigibedq6f0k.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://b01cffea-7a05-49e8-9781-04202a21c04b.filesusr.com/ugd/d5d855_396a9be2ba284caf835027e11a64fe59.pdf?index=true
    • https://9e730ba1-499c-413e-9a09-8a81f8121270.filesusr.com/ugd/0a0016_f06534734af944cab1397c82a7e1de77.pdf?index=true
    • https://s3.amazonaws.com/juvuraguvutoxif/acid_bases_and_salts_worksheet_class_7.pdf
    • https://61249681-e2d1-4375-841a-b3723294d79c.filesusr.com/ugd/3d514e_01e06a409a644d6080b887d372c60c57.pdf?index=true
    • https://9d349da1-218b-4b59-9e37-2a90cab56d40.filesusr.com/ugd/de9003_c8c17a6d7c484e3e906ca53706328168.pdf?index=true
    • https://88749095-6fd7-453f-8e8a-15b48fe47dd1.filesusr.com/ugd/e4d7df_5992b4687b2844dca8c3df239e8c6918.pdf?index=true
    • https://9764c975-acb6-4bd5-a3ff-b1f4624bc9bc.filesusr.com/ugd/5bcb7b_5d332ab56512455e9941f37a38be8978.pdf?index=true
    • https://d73c234d-0e3d-497d-8108-d5659bace061.filesusr.com/ugd/58a813_d720d89cd0b24807b52b20c351bbb8cc.pdf?index=true
    • https://13006a6e-9b3f-4191-9e3f-064114488741.filesusr.com/ugd/34464a_afd1ffca09314c5e8d4893f0cb9ce104.pdf?index=true
    • https://e8b83640-91e4-44a0-a69f-c2468797902f.filesusr.com/ugd/ee4a13_0b4b359d64164eb397193b5bee3b67e2.pdf?index=true
    • https://ec560393-4650-4708-bf0c-d08fceb8458c.filesusr.com/ugd/ca69db_39625e0b9f544c4ead6102e329df2a1e.pdf?index=true
    • https://1682489e-d94b-4f22-b6a6-c8ecb623ca2e.filesusr.com/ugd/5f226e_51e10a85ba41474aa468400a4789012d.pdf?index=true
    • https://s3.amazonaws.com/tokit/sofaperatugijo.pdf
    • https://35479656-6a94-44d6-ac55-da507c14a2ae.filesusr.com/ugd/d68318_4c43d8f843834dedb9663e421d7f8980.pdf?index=true
    • https://s3.amazonaws.com/fosalizuzu/cartomancy_card_meanings_combinations.pdf
    • https://d21da297-2d1c-4020-882f-059d99c29dc9.filesusr.com/ugd/3724a2_e6b2482fe61a4b8c9212056db0b8fb91.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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e1fb.bin
34efd9ee29a7f52e17549037fa53747af244813994d30eb565a806dc436a6364
pdf-font-stream PDF embedded font (sfnt) at offset 0xE1FB 5652 bytes
font_01_sfnt_off0000f51d.bin
f883b2fbd31083032d51a4b583eafb380ae256e4e7d07d82bdccf75b84c8f86c
pdf-font-stream PDF embedded font (sfnt) at offset 0xF51D 11988 bytes