Malicious PDF — malware analysis report

Static analysis result for SHA-256 82d93ccbb53f00ee…

MALICIOUS

PDF

84.8 KB Created: 2021-03-31 07:27:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-16
MD5: ca326643abf525ec4d0d3498c708b75e SHA-1: bb0c3e16d6699bc8372a561be2839bd84dfb7a38 SHA-256: 82d93ccbb53f00ee1f8c9f1621a3de8a65184b0641aa05fe8e5d32fa00042ab1
186 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier, and contains numerous external links. The document body, though heavily obfuscated, suggests a lure related to an 'answer key'. The presence of multiple external links, including one to 'ponafet.ru', indicates a likely attempt to direct users to malicious or phishing websites, consistent with a link farm or phishing attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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 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://ponafet.ru/123?utm_term=heats+of+formation+answer+key PDF link annotation
    • https://cdn.sqhk.co/dejuxafe/eoFhcjh/college_board_ap_chemistry_free_response_answers.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4460251/normal_6057a6ad5695c.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4415742/normal_5fe1cd385afac.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4411935/normal_602d2b9fe4580.pdfIn PDF document text
    • https://cdn.sqhk.co/pagozixupezi/iizhdie/bleach_blade_battlers_2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4409840/normal_604d96151e637.pdfIn PDF document text
    • http://wizudaneku.iblogger.org/anoreksia_nervosa_adalah.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4457281/normal_6041c74cd1b77.pdfIn PDF document text
    • https://cdn.sqhk.co/lixipadiwel/7GJSgge/82190409851.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4494139/normal_60082d04b7596.pdfIn PDF document text
    • http://bezinawevudo.22web.org/shadowrun_returns_install_mods.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4465277/normal_60400566a32c9.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4492529/normal_60063393eece8.pdfIn PDF document text
    • http://geesecam.com/blankets_graphic_novel_reviewm0t9t.pdfIn PDF document text
    • http://vwwv-avito.online/dafasojinorbwfsv.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://b46c4cda-4951-41c0-816f-bbf02eee4d9b.filesusr.com/ugd/4ff992_22677cc27f834c19a377a45ecf33a486.pdf?index=trueIn PDF document text
    • https://dd54f144-242a-4a88-9385-6c39f9996aab.filesusr.com/ugd/9f32c1_c05472b16d034e879f0deeabb5f9b869.pdf?index=trueIn PDF document text
    • http://botujovibal.rf.gd/dod_cloud_computing_security_requirements_guide_2017.pdfIn PDF document text
    • https://6cdf8c5e-36a0-4b6d-987f-32d3d50030cd.filesusr.com/ugd/3c2e2e_ab69257aebfd41158e76236bd82a7ef9.pdf?index=trueIn 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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f7e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7E6 5100 bytes
SHA-256: 3dd8d487671a2e12d7ab8039f34d4e4fadf3f7713aa7f357f4b3471a182d6d7b
font_01_sfnt_off00010946.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10946 11412 bytes
SHA-256: 0c126901e7006a0d77145c462e0907d65dc2f70edfdac461d30559f624c8a401
font_02_sfnt_off00013047.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13047 16152 bytes
SHA-256: 70180b97a9b9fe0de1e0c05b06d733d04658c9f7a2923a3eee6842afe753d47e