Malicious PDF — malware analysis report

Static analysis result for SHA-256 4903aac76fa3687a…

MALICIOUS

PDF

96.9 KB Created: 2021-06-08 19:24:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: 41e5802c0f83d493bf30c35faa870763 SHA-1: 9a28b68891c1c1a0d356eef881054e7dc2eb7277 SHA-256: 4903aac76fa3687a4296130e7abbd9892d4c14a264d8964f1744d8c80f2c6127
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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=hangul+chart+korean PDF link annotation
    • https://lofugaliwowutuw.weebly.com/uploads/1/3/5/2/135299309/kusovukosejezuxivum.pdfIn PDF document text
    • https://numesenara.weebly.com/uploads/1/3/1/0/131069843/ba03598848ff.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4426270/normal_5fff78a49d68e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4473903/normal_5fd946b5112bd.pdfIn PDF document text
    • https://wovuxekas.weebly.com/uploads/1/3/4/3/134379471/7833398.pdfIn PDF document text
    • https://fisabovetusita.weebly.com/uploads/1/3/4/5/134597566/5960178.pdfIn PDF document text
    • https://rulodewarozuw.weebly.com/uploads/1/3/4/6/134678260/borukusik_pogedi_jemuxe_pemujewiru.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/5f94cc60-9441-4f71-b403-0f8d61546872/tuvazaxagul.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b3565d08-ea6d-4af3-b4df-f4328e273cb9/jekuminedelilabalijaje.pdfIn PDF document text
    • http://jagimikat.pbworks.com/w/file/fetch/144735246/bomuxalir.pdfIn PDF document text
    • http://kivupored.pbworks.com/w/file/fetch/144718992/nizegeruwofevakasotem.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7a55ac97-3146-46ee-8c5a-31f8450b9d97/how_to_charge_a_jump_start_battery.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2a0f2f6a-a481-4dd3-abb3-49d9fe369c88/maytag_bravos_xl_washer_will_not_turn_on.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/71a7e401-0867-40a4-b78a-6d13ed1e796f/the_standard_401k_advisor_login.pdfIn PDF document text
    • http://kuzimotum.pbworks.com/f/temevu.pdfIn PDF document text
    • http://nigezid.pbworks.com/w/file/fetch/144427197/5359460800.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f8d36d84-ef21-4162-9b13-2f3836a5d24d/rash_on_my_babys_face.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/89e37d87-b439-45e3-9c2e-7b2ed3795495/puxevipokeneladi.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c8e4bb39-5d92-40bf-aae3-0f6c8e108823/tax_deductions_for_working_from_home_2019.pdfIn PDF document text
    • http://detomipipu.pbworks.com/f/tubemate_apk_download_new_version_2020.pdfIn PDF document text
    • http://pobonagul.pbworks.com/f/xenupawali.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f4bcc1b1-d061-4ad3-9d86-12c41268e776/beats_solo_wireless_guide.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000109d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109D4 7708 bytes
SHA-256: 52f93f77803ca87cfa2091421eb3e1de20d518bcf19ae929a989c5a30e5726ed
font_01_sfnt_off00012422.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12422 4908 bytes
SHA-256: 5847d57966c840d41f6963798e0e4bddee9c80a8e8b3f13976195c70e1937537
font_02_sfnt_off000134cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x134CB 12280 bytes
SHA-256: ef3ddf4eec2a4091ef61e8eb90f5184670a63fa3d768849b3b8e4ab6a0151dde
font_03_sfnt_off00015ef1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15EF1 16552 bytes
SHA-256: 7719f31e2a6b22e07076c4ef92f436e71306070084ac24c62a0207bcc29446b6