Malicious PDF — malware analysis report

Static analysis result for SHA-256 8bd9479fecfa7d24…

MALICIOUS

PDF

74.3 KB Created: 2021-03-25 16:18:08 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: 3a9cd762c70db34c3ef16019116b1984 SHA-1: 29ba0d7615817b0d78843d854aad052854ff0c3c SHA-256: 8bd9479fecfa7d245164e98a7327b14318428d69a87a8e4d75ddac28d294d688
244 Risk Score

Malware Insights

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

This PDF file was flagged by multiple critical heuristics as malicious, including a redirector link and a large link farm. The ML classifier also strongly indicated maliciousness. The embedded links, such as https://dafemum.ru/strik?utm_term=should+residential+schools+be+capitalized, suggest a phishing or spamming attempt, likely delivered as a spearphishing attachment. No scripts were extracted, but the PDF structure itself is used to host numerous external links.

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
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://dafemum.ru/strik?utm_term=should+residential+schools+be+capitalized In PDF document text
    • https://bivovupoxewoko.weebly.com/uploads/1/3/1/3/131380626/dupumu.pdfIn PDF document text
    • https://cdn.sqhk.co/kixowijeka/gAUjhe3/the_chosen_one_book_series.pdfIn PDF document text
    • https://cdn.sqhk.co/ditetona/didC5YR/user_guide_for_dji_osmo.pdfIn PDF document text
    • https://cdn.sqhk.co/ferorigife/Uahiuhg/rawanegunokonogalu.pdfIn PDF document text
    • https://cdn.sqhk.co/kajurineg/f0njdih/energy_joe_mod_apk_download.pdfIn PDF document text
    • https://delimilakemasuj.weebly.com/uploads/1/3/4/4/134400920/88317ce25a5b38e.pdfIn PDF document text
    • https://xunatejasadar.weebly.com/uploads/1/3/4/8/134882749/c456f8184d6c.pdfIn PDF document text
    • https://cdn.sqhk.co/kitujesijak/gerdhz7/49993699232.pdfIn PDF document text
    • https://siweporabid.weebly.com/uploads/1/3/5/3/135345409/wesijiresududi.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://lojurixerura.epizy.com/antithrombotic_therapy_guidelines_2019.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8608b3ab-767a-483e-838e-286f89ed9abc/why_wont_my_galaxy_note_5_turn_on.pdfIn PDF document text
    • http://tuxusajef.rf.gd/star_spangled_banner_sheet_music_easy_piano.pdfIn PDF document text
    • http://nifekubipaxo.epizy.com/medical_careers_list_a_z.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/80d769eb-dbc4-4b7b-b8cb-e5b70dc1909a/george_foreman_electric_bbq_grill_cover.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1737216f-bbb9-4c34-91b6-8c4a5fce6914/tiguxaxan.pdfIn PDF document text
    • https://5053e88e-9e18-4719-890c-32a1cca0295d.filesusr.com/ugd/411503_76f88c0243834f0194e1d5b46bb1aee5.pdf?index=trueIn PDF document text
    • http://ratotepuno.rf.gd/old_audio_song_bangla.pdfIn PDF document text
    • http://vasikiga.epizy.com/juxigumoduwobobevu.pdfIn PDF document text
    • https://729282ec-1290-4cbc-9302-cf8a24acd4c7.filesusr.com/ugd/42c189_a7707a4c7b2a49c7bb6c84fea24dec88.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_off0000e3a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE3A1 5456 bytes
SHA-256: a1455d280a95ff6dd2f95e796afea6f4672ecc38e31d65633e2cbb1fed3f4ce7
font_01_sfnt_off0000f620.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF620 11116 bytes
SHA-256: ec5171f063f5b368bb9091dfca0beabca3878d4eb3697ced815912c4dd445e86