Malicious PDF — malware analysis report

Static analysis result for SHA-256 f71ac808c9c9f6d4…

MALICIOUS

PDF

84.4 KB Created: 2021-06-06 00:58:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 8cf7a8320d9146a27ba30ddba6dc6da3 SHA-1: 4015bae675369079992ca13571921c49aacb68b7 SHA-256: f71ac808c9c9f6d42cdca8fa8e6732ebd4974f80328f4c0632f6ec0f09d00456
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of external links, many pointing to disposable hosting, suggesting a link farm or SEO spam operation. One of the primary external links is to 'synerhu.ru', which is likely part of the malicious infrastructure.

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://synerhu.ru/pbw?utm_term=what+is+the+best+diet+pill+for+belly+fat PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4455179/normal_604fff352b871.pdfIn PDF document text
    • https://maduzoxunixeg.weebly.com/uploads/1/3/0/7/130775653/mudotu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4411219/normal_604693ae29999.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4490244/normal_603ee58e0d364.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366952/normal_6033002049fd7.pdfIn PDF document text
    • https://nenesasexogo.weebly.com/uploads/1/3/5/4/135400776/bubus_zofogo.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/41a14a10-e196-4b78-9e47-2e3203cee22c/classify_each_triangle_by_its_angles_and_sides_worksheet_answers.pdfIn PDF document text
    • http://lamedivu.pbworks.com/w/file/fetch/144607968/what_are_the_features_of_news_agency.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/83b8d449-0d48-45a4-8017-2472df5af306/whistler_inspection_camera.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2759d844-0d33-419f-b434-3c73b9aef622/susidogotomugaf.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e1c42592-dd11-4d57-8f81-3708d7da0059/used_bowflex_xtreme_se_for_sale.pdfIn PDF document text
    • http://kevesefazoga.pbworks.com/f/animal_war_game_ios_2019.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/171de5b6-c845-48c6-8ee6-e80b038ef9ad/botururomavesofinaw.pdfIn PDF document text
    • http://gepefupugalu.pbworks.com/w/file/fetch/144687237/ralowokinibaduvapexetiwu.pdfIn PDF document text
    • http://fadoposapat.pbworks.com/w/file/fetch/144477294/engineering_drawing_and_design_notes.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3a04d789-2277-4b6f-97d3-7bc21be542ed/adb_install_android_app_apk_system.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/18e6cc0c-338b-4bae-bb2c-0a2af534887b/does_iphone_12_pro_have_nfc_reader.pdfIn PDF document text
    • http://wuranosa.pbworks.com/f/how_to_consolidate_data_from_multiple_workbooks_in_excel_using_vba.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
    • 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_off0000f2a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2A0 5384 bytes
SHA-256: 8eecfd8c993d8e60632241f04583007bc7cc5ede0112a6b8b172d92d4a85b964
font_01_sfnt_off000104f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104F8 12124 bytes
SHA-256: b390f379dff368b9f4f9e77ed1e8fb81d197cdaa9e479d3eef068d5b29ff4739
font_02_sfnt_off00012d97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D97 16060 bytes
SHA-256: 2173a1880e9f774f759393e7d0d28dda91d04d8a3eae6bea41b822770b343b90