Malicious PDF — malware analysis report

Static analysis result for SHA-256 18831b3b6da855f4…

MALICIOUS

PDF

77.1 KB Created: 2021-03-28 12:48:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: 5a3b83585a93c1945371cfff27310850 SHA-1: f2cf4d1f060ca39800991799fa5511a549e0bc0a SHA-256: 18831b3b6da855f4dd1ee88656ec74509ad622e2101d9eacbb60a8b60a25b365
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of external links, many pointing to disposable domains, indicating a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or SEO manipulation. The embedded URLs and the nature of the link farm suggest an attempt to drive traffic to potentially malicious content or for SEO poisoning.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

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://jacksth.ru/strik?utm_term=labview+core+1+exercises+2018 PDF link annotation
    • http://bristol-yalta.run/running_lean_carmdosy.pdfIn PDF document text
    • http://zatawonilar.iblogger.org/how_to_set_g-shock_time_zone_malaysia.pdfIn PDF document text
    • http://shopsupergood.site/los_chakras_de_la_tierraiewgg.pdfIn PDF document text
    • http://mizusowe.66ghz.com/inheritance_cycle_book_4.pdfIn PDF document text
    • http://aycotoro5.xyz/ghost_tower_of_inverness_mapjc170.pdfIn PDF document text
    • http://azakalaza5.xyz/3565637897nezgn.pdfIn PDF document text
    • http://lalashoppen.online/12280794533av5iy.pdfIn PDF document text
    • http://tenipimutav.mywebcommunity.org/54634487731.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://xetubuvij.rf.gd/capecitabine_mechanism_of_action.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7a77c998-c7b3-4094-90be-a7b8e0644b04/is_a_negative_scale_factor_and_enlargement.pdfIn PDF document text
    • https://94226b1b-8363-4ad6-a779-e61b7b16ff5b.filesusr.com/ugd/b3bc21_94a1377ee4e14bccb47d4332129c7c05.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/fd7a44a8-9864-4898-a1ed-7025e1695fa1/kozisisuru.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5100dea0-b104-40e2-b91f-564f8e14a211/what_are_the_hours_for_walmart_photo_center.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a5ebc44d-d94c-4a63-b93e-ae4a2fd105b8/viweturunefani.pdfIn PDF document text
    • http://nokejufesuw.atwebpages.com/88306706022.pdfIn PDF document text
    • http://pedamodaw.onlinewebshop.net/nodusas.pdfIn PDF document text
    • https://c183b790-cb34-49aa-848e-1a9f2b14dda3.filesusr.com/ugd/d8966e_e8526d1925c8459782ffdc8a3d4289ef.pdf?index=trueIn PDF document text
    • http://jafixomedimun.onlinewebshop.net/architectural_drafting_for_interior_designers.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9bcf7a24-8d3e-4b6c-84f8-20f5980c72d9/i_spy_with_my_little_eye_meaning_in_hindi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/15f57b4f-a780-46a0-990b-b03ecb153d00/3_4_taza_de_harina_a_gramos.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/39f7cb63-e018-4575-adf6-2e3723ed9a89/how_to_end_wall_street_journal_subscription.pdfIn PDF document text
    • https://cd753cf5-d90a-4073-9c55-931a76e81761.filesusr.com/ugd/8826df_09fd8658b1c4425bb21decd29a1d1c7f.pdf?index=trueIn PDF document text
    • http://bizosubage.rf.gd/58999793728.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6435a1a0-979b-43d1-9042-ac60d32c0aa2/rounding_numbers_worksheets_with_answers.pdfIn PDF document text
    • http://metepukiwameme.epizy.com/fusiform_aortic_aneurysm_ct.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_off0000e00c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE00C 5184 bytes
SHA-256: 6e572e5f417c4d7ba544be80622b39b72d6c9ae90734349804d4c22762bbbc0e
font_01_sfnt_off0000f1cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1CC 11268 bytes
SHA-256: 829c0629030c29f40b603ff171ac0c1fe1ed338689a18eb73ce34508b14b4e7b
font_02_sfnt_off00011847.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11847 4324 bytes
SHA-256: ce7e2e230a41ba6fc2d7d2240890c8289d67876d84a3d076d67c0b48111c8230