Malicious PDF — malware analysis report

Static analysis result for SHA-256 13674f3de4be5beb…

MALICIOUS

PDF

71.5 KB Created: 2021-03-30 02:27:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-02
MD5: 7e4e5535c5b1c254ec097be410bd5b34 SHA-1: 41473199c72fffddf3f3008ad7353821f295c734 SHA-256: 13674f3de4be5beb98e64471dfa41411bfc41921986a0780d5ff83d8217b7593
186 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many hosted on disposable domains, suggesting a link farm designed to redirect users to malicious sites. The heuristic 'PDF_SEO_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly indicate this behavior. The ML classifier and ClamAV detection further confirm its malicious nature, flagging it as phishing or a trojan. No scripts were extracted, but the embedded URLs are the primary indicators of compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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/wix?keyword=practice+problems+for+diffusion+and+osmosis+answer+key PDF link annotation
    • https://cdn.sqhk.co/dajuzafum/dhbja8n/nijolibaxibelebabize.pdfIn PDF document text
    • http://inertbhjbj.ru/966686622138btj3.pdfIn PDF document text
    • https://cdn.sqhk.co/nodujugebi/AWUbWhf/battleship_puzzles_warship_empire_cheats.pdfIn PDF document text
    • https://cdn.sqhk.co/toxodimina/fjbhdhf/8738734920.pdfIn PDF document text
    • https://cdn.sqhk.co/fikalibumi/hcra4ha/17418153035.pdfIn PDF document text
    • https://cdn.sqhk.co/xokebuzizo/aRjbrgd/fly_singing_bird_fly_lyrics.pdfIn PDF document text
    • https://cdn.sqhk.co/gafazakedoki/jkRtR8x/79888842590.pdfIn PDF document text
    • https://cdn.sqhk.co/gidufulelav/3iahbOk/cure_in_chinese_language.pdfIn PDF document text
    • https://cdn.sqhk.co/bawevabob/TuG7YCG/91536479167.pdfIn PDF document text
    • http://tikovg.xyz/226853371317h6tc.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://58960a86-a3f4-42d8-866e-ee2cf32068b1.filesusr.com/ugd/1ad962_233361176a20450c9acbde1a8ba521fd.pdf?index=trueIn PDF document text
    • https://c2093f15-f4fb-4bda-9582-db5404103fa6.filesusr.com/ugd/b28561_0688324cab6044a4987ddeac986ffc63.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/vanatul/multiplication_worksheets_with_answer_key.pdfIn PDF document text
    • https://80b2a579-f9ed-4aa0-b91a-ac3c8973c086.filesusr.com/ugd/353d00_e3e896a75a514e678cb63bb90207e2c6.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/belopudevuzuza/97216646912.pdfIn PDF document text
    • https://435a888a-8f80-410d-aa77-77edd6e4491d.filesusr.com/ugd/51fec0_94cdaa0d85e24199b4dcc4ef9d30bae9.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/nufidibodudulad/motorcycle_engine_oil_guide.pdfIn PDF document text
    • https://66f9c2bc-82a6-463d-9ccd-9c94d3d8805e.filesusr.com/ugd/b361c6_5d2630b7123c44fd9a1748626faae8ab.pdf?index=trueIn PDF document text
    • https://c1d61d78-9bae-425c-b347-ee91470fe4f1.filesusr.com/ugd/60933b_6324a27698a847d6badcc37019c925d4.pdf?index=trueIn PDF document text
    • https://3633ae4e-9acc-45df-885e-1bfa1481cb44.filesusr.com/ugd/e73054_f06f488e46864dbeb3edf6805e30bddf.pdf?index=trueIn PDF document text
    • https://39c1d623-eccb-4af0-a86a-15328a2d61f9.filesusr.com/ugd/3cb6cb_cd85674eb9ca40d4923c199fa2d7a6de.pdf?index=trueIn PDF document text
    • https://acda325f-ee3b-40e4-882f-fabc489a6840.filesusr.com/ugd/23b3d3_6a48233e7a3d46799acc253b946663e6.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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000da29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA29 5700 bytes
SHA-256: 421b98fca4990fbba4500468c9c039f3101e48538f544e0ba8df374c99232e3c
font_01_sfnt_off0000ed87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED87 10240 bytes
SHA-256: f3428fa49a98cb42b72d7f449f9547e1e402e848164c61689fcf60044e7d78d2