Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4d3da15e716be91…

MALICIOUS

PDF

92.5 KB Created: 2021-04-03 15:33:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 3a690b388abcaa76fae22f585829dc54 SHA-1: ca3a1a541c4fe49407cbf0be065e5b725c7d7c1d SHA-256: b4d3da15e716be917b296937a9b0a02e07ea544906f71a5ef3f1d4a64a3d4b1a
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, with several pointing to disposable domains and one specifically identified as a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and does not provide clear textual lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 5

  • 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://pelibifir.ru/award?keyword=azorin+poemas+pdf PDF link annotation
    • http://kipoxepufe.iblogger.org/why_do_i_feel_pain_when_someone_else_is_hurt.pdfIn PDF document text
    • http://bestita.space/93053485657qc613.pdfIn PDF document text
    • http://bobatorosas.mypressonline.com/english_grammar_rules_in_urdu.pdfIn PDF document text
    • http://helplnstagram-confirm.com/48389607695b6cat.pdfIn PDF document text
    • https://cdn.sqhk.co/limizolaxa/2jexzhj/foro_excursiones_cruceros_mediterraneo_pullmantur.pdfIn PDF document text
    • https://cdn.sqhk.co/jejefudebuxi/fnEbf8L/bikeniludu.pdfIn PDF document text
    • http://priz24.site/internal_structure_of_a_leaf_worksheet_33g2mti.pdfIn PDF document text
    • https://cdn.sqhk.co/tusufawenu/fgijghd/10992426135.pdfIn PDF document text
    • http://goxonivibewe.22web.org/althusser_reading_capital.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • http://taxowojo.epizy.com/bmw_335i_auto_vs_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9fa05dcc-ae2b-43ed-a0df-e237727d145b/28534750520.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/afedba4c-8d59-4dd9-9e7e-2836364d289f/negimuwonifejibolabene.pdfIn PDF document text
    • https://s3.amazonaws.com/gimisorixosu/puvorobewedidataba.pdfIn PDF document text
    • http://funegabupeg.rf.gd/pensum_medicina_uasd_plan_14.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/36f9f0d5-aa60-497e-9afb-4c2b73b953aa/best_price_bushnell_trail_camera.pdfIn PDF document text
    • https://s3.amazonaws.com/xovekolamoxe/free_backgammon_game_for_ipad.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/77d8c30f-fd96-47a9-bdb3-72f6152131f7/how_to_change_my_infrared_thermometer_back_to_fahrenheit.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2f55361a-4e2d-4888-a0a5-f08a2ee4d7b8/worlds_in_collision_amazon.pdfIn PDF document text
    • http://jokosen.atwebpages.com/49416057331.pdfIn PDF document text
    • https://s3.amazonaws.com/zunewidimem/71868896458.pdfIn PDF document text
    • https://s3.amazonaws.com/genukopapovixo/geganug.pdfIn 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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011f58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F58 4900 bytes
SHA-256: 357814cf6c3dd53d81c2ab57c507ca1dc69ceea0a35129beb55087df0f9b538a
font_01_sfnt_off00012fd7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12FD7 11440 bytes
SHA-256: 9aee7471575e17cc4842e905b3c1c4413b48b0c7a5d9831a9eb5754ad734d9c1
font_02_sfnt_off00015519.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15519 4324 bytes
SHA-256: cd94ef65598b1866d0653cdd88243d989fd81359c0e770c2d3a4858f1c2f6d34