Malicious PDF — malware analysis report

Static analysis result for SHA-256 ec9a00488918ac46…

MALICIOUS

PDF

80.7 KB Created: 2021-04-01 03:39:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: a15f5e19a15ea075a1aa040795f2290a SHA-1: 235fc790effe1d6c28f9c9173a4d4ef1c5122b81 SHA-256: ec9a00488918ac46e4c1c38c69cfec01ee5c16f4231760dde3522d7e5652609d
186 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. The primary function appears to be a link farm, containing numerous external URLs pointing to other PDF documents, some hosted on disposable domains. This suggests an attempt to manipulate search engine results or distribute further malicious payloads. No scripts were extracted, but the presence of many external links is a strong indicator of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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 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://seumenha.ru/award?keyword=data+validity+and+reliability+in+research+pdf PDF link annotation
    • http://urro-hu.com/22612001729tqi17.pdfIn PDF document text
    • https://cdn.sqhk.co/tawunipufop/arHgjcU/kumisalosebe.pdfIn PDF document text
    • https://cdn.sqhk.co/risenulowo/ji5NN3b/demon_slayer_rpg_2_wiki_breathing.pdfIn PDF document text
    • https://cdn.sqhk.co/futevanu/higeige/splash_snake_vs_blocks.pdfIn PDF document text
    • https://cdn.sqhk.co/kigoxeni/aihzGgg/13202962151.pdfIn PDF document text
    • https://cdn.sqhk.co/tidaxetosi/eytidih/guxujezuwujo.pdfIn PDF document text
    • https://cdn.sqhk.co/darojopul/ifAhdhd/anime_character_maker_app_apk.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4484364/normal_60254c3ba4920.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383579/normal_5fe804e3c1117.pdfIn PDF document text
    • http://cashbackk.site/xepesututubudinabh68nv.pdfIn PDF document text
    • https://cdn.sqhk.co/fowifabibu/Kgf1jiT/offroad_racing_buggy.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://ded05c8b-f0d8-42bc-a64b-daa0b63394ca.filesusr.com/ugd/99afdc_7d50e545ba084e14a5898e6ca0e0e39b.pdf?index=trueIn PDF document text
    • https://9f503c4c-bf14-4dcb-9a7a-68e0e5bb3568.filesusr.com/ugd/8ac1ab_c75cb37afb874eef9c0be05a4bef8e3a.pdf?index=trueIn PDF document text
    • https://45f91bdd-2b68-4e60-ae2c-b14373ae5332.filesusr.com/ugd/0d089b_223db2b4cc474942b451bd38834283db.pdf?index=trueIn PDF document text
    • https://70010cfe-69b1-4fe9-a336-bdfe2418dc1e.filesusr.com/ugd/f1d680_607041aa8b8c450f911887aea395a0d0.pdf?index=trueIn PDF document text
    • https://e31b828f-dd5d-4b35-abba-5777d5fc2ed6.filesusr.com/ugd/56a8cc_c6695a100b5140288333e09c2e85ac1d.pdf?index=trueIn PDF document text
    • https://45ed8376-e832-497f-ab20-0a31924dc5db.filesusr.com/ugd/4b7290_9e6565c74e3148d2b8b0fb04f9365957.pdf?index=trueIn PDF document text
    • https://f8bd9030-4518-40b4-9047-d478e6ffc17b.filesusr.com/ugd/608fe2_65aae6e8b46f40e8893419f1021acd66.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_off0000e4fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4FC 5544 bytes
SHA-256: 292af31a3245fee1ff3545276ed9e22aeaadf88d45d757aaeff90d5d821dfc28
font_01_sfnt_off0000f7da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7DA 11308 bytes
SHA-256: ac381d6567b21a25a59c366200c189bb7fececff1175c551adee72d8344f6cc1
font_02_sfnt_off00011e13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E13 16232 bytes
SHA-256: 68eef4b610644b6a98f668349b58b424e8310755c20c018328a8321db0e17a89