Malicious PDF — malware analysis report

Static analysis result for SHA-256 1b9ea9048038bdee…

MALICIOUS

PDF

83.0 KB Created: 2021-03-17 19:22:45 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-16
MD5: 3efa7fa68c0357f643055a9cdef01507 SHA-1: 24ad513c267fcc522fff59ebc035520ff72ce722 SHA-256: 1b9ea9048038bdeed889cd9b90e55d4f1657262f06a2012e967424408c28b786
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links pointing to disposable domains, indicating a link farm or SEO manipulation scheme. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or distributing further malware. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool often used to create PDFs from web content, which aligns with the link farm heuristic.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://fokemale.ru/strik?utm_term=how+to+use+welding+symbols+in+drawing PDF link annotation
    • http://ramuwazezu.22web.org/xijape.pdfIn PDF document text
    • http://daating19.site/xupuperexajewesazomd29p4.pdfIn PDF document text
    • http://jalojewaga.mypressonline.com/99385206724.pdfIn PDF document text
    • http://familyit.pro/26337664954uh6sq.pdfIn PDF document text
    • https://babexunerasosib.weebly.com/uploads/1/3/4/6/134620176/5482209.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4390642/normal_6028953f8ebd8.pdfIn PDF document text
    • http://mon-cmbretagne.best/49008740056yfmel.pdfIn PDF document text
    • https://munopufunorari.weebly.com/uploads/1/3/4/8/134881547/d693c0c64c.pdfIn PDF document text
    • https://jamafijuzu.weebly.com/uploads/1/3/1/4/131437216/2390736.pdfIn PDF document text
    • http://lalat.space/integer_word_problems_grade_8meyql.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4475577/normal_5fe875d5df551.pdfIn PDF document text
    • http://sigixexizo.sportsontheweb.net/calendario_laboral_2020_malaga.pdfIn PDF document text
    • https://jadusulad.weebly.com/uploads/1/3/4/7/134764450/nadagimisuje.pdfIn PDF document text
    • https://dunopugagikevu.weebly.com/uploads/1/3/4/7/134728147/zotisavef-jilomawa-tivud-mazijogofuzop.pdfIn PDF document text
    • http://italy50wow.pro/61452041830m6fwh.pdfIn PDF document text
    • https://jekudadej.weebly.com/uploads/1/3/5/3/135301654/e087c68c84031f2.pdfIn PDF document text
    • https://kagebavewijove.weebly.com/uploads/1/3/0/7/130740568/8a90ce97acac708.pdfIn PDF document text
    • http://ramuwesitavoz.mywebcommunity.org/dekexik.pdfIn PDF document text
    • https://rudunusom.weebly.com/uploads/1/3/4/6/134602981/zakameg.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://fubavinexazixo.onlinewebshop.net/relation_and_function_in_math_examples.pdfIn PDF document text
    • http://xizewipuf.rf.gd/83804596720.pdfIn PDF document text
    • http://jetotajasavesi.atwebpages.com/songbook_with_guitar_chords_free_download.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_off0000f9cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9CB 5320 bytes
SHA-256: c35503d21cbed51e49d97ec6f9f40681b1e2069a04b111f28f922fed30d67ddd
font_01_sfnt_off00010bcb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BCB 10668 bytes
SHA-256: 11a94f8519b77a6258f416d49201ce7338e581842546c5ac30160226def4daa2
font_02_sfnt_off0001300b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1300B 4324 bytes
SHA-256: cd94ef65598b1866d0653cdd88243d989fd81359c0e770c2d3a4858f1c2f6d34