Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8bf4ebd27e9b3a4…

MALICIOUS

PDF

82.8 KB Created: 2021-03-17 03:23:00 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-02
MD5: a7414f64ef8576b5bb15194032da2750 SHA-1: 6bd2b6e47635ef08b441e6d741b703a100b8d713 SHA-256: a8bf4ebd27e9b3a43feb20938f73cb93a67fdb63b4d457f6c8271723bc920665
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a large number of external links, identified as a link farm, with the primary URL suggesting a lure related to 'guitar lesson chords pdf'. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution through these numerous external links. The file's structure and content suggest it's part of a campaign to drive traffic to potentially malicious or deceptive websites.

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://bologen.ru/award?keyword=guitar+lesson+chords+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4369498/normal_60223b54571b1.pdfIn PDF document text
    • http://tuwukadinem.mygamesonline.org/65648149519.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4381105/normal_6000766547b92.pdfIn PDF document text
    • http://sazinoz.mypressonline.com/the_vedanta_way_to_peace_and_happiness.pdfIn PDF document text
    • http://taygerr.com/how_many_calories_are_in_bow_tie_pastae51lj.pdfIn PDF document text
    • http://opensalon.xyz/mifosupawogilijefo2hpb5.pdfIn PDF document text
    • http://leziwazedo.mypressonline.com/tips_for_public_speaking_and_presentation_skills.pdfIn PDF document text
    • http://vituloza.sportsontheweb.net/required_documents_for_hawaii_state_id_renewal.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://d8d078ea-10ec-4787-8e21-ef6e32b87a24.filesusr.com/ugd/8f6098_6992306309214302b568c5a91b6b9c46.pdf?index=trueIn PDF document text
    • https://081e7fb2-604d-424b-9b75-a58d54a71a44.filesusr.com/ugd/abd6ea_2b938fadecdf4430976bb74ca427426b.pdf?index=trueIn PDF document text
    • https://7ae52be2-ba3c-41fb-8935-29281088223e.filesusr.com/ugd/affaa6_9f6b68801b474baa8a9a36471fa5adb9.pdf?index=trueIn PDF document text
    • https://95043331-d9de-4498-ad98-35b8ac3ee23f.filesusr.com/ugd/5740b2_6cccaa64f8684b1e95cbc5eb75f4c59a.pdf?index=trueIn PDF document text
    • https://fc06435f-e709-4c80-b59d-96fa470c1a13.filesusr.com/ugd/bdc04d_b69e2d11485d4bd4ab2316d3a9bc5fba.pdf?index=trueIn PDF document text
    • https://35548484-ce42-4b18-9d9d-834326683263.filesusr.com/ugd/a221b6_54c4d9d864ca48c5bd6f82944b54b3e5.pdf?index=trueIn PDF document text
    • https://ce2645ba-e89a-43d5-afff-5c0150757291.filesusr.com/ugd/c63dba_db540e461a5f4175861c384bd8da6220.pdf?index=trueIn PDF document text
    • https://1fae3a98-13b7-4b95-b1f0-1fbd1b7b0aee.filesusr.com/ugd/1da05d_1ca359e004c34e17b6a8496c5e8f5790.pdf?index=trueIn PDF document text
    • https://964beff5-d24f-450a-94e2-fa7e9faef44a.filesusr.com/ugd/61158f_9d45909575fd429b87dfa55965bb2b30.pdf?index=trueIn PDF document text
    • https://9e6c4f0b-3406-4274-bf8a-5be7f948d240.filesusr.com/ugd/45c6ff_4b9b744e3af64591a7e4725cef6f3b33.pdf?index=trueIn PDF document text
    • https://d7ae471b-a447-437d-81b4-4e603f8679d9.filesusr.com/ugd/0a3240_e43ab189ddab43f29305c55310c20140.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_off00010696.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10696 5272 bytes
SHA-256: dae764d4702833a5cda59ac113cce880bed40e775c26f21cca1c9f839de34c6a
font_01_sfnt_off0001187e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1187E 10984 bytes
SHA-256: e9dcf35f244040960028d67895b458c35c48a2d881ee8e00c5623c5dce4351a3