Malicious PDF — malware analysis report

Static analysis result for SHA-256 7890b9cfdce897ce…

MALICIOUS

PDF

82.1 KB Created: 2021-03-19 04:01:32 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 366ae53d7b380eb19f8d65f76664ec13 SHA-1: 2c0e54897927fc3e09dfdf9d9e7802e575c7a4d4 SHA-256: 7890b9cfdce897ce7b9324f12a9a8d13eff57775c3149dfd86a70b6b37098a8b
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

The PDF contains numerous links to external websites, many of which are hosted on disposable domains and appear to be part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body, though heavily obfuscated, suggests a lure related to 'physics equations of motion class 9 questions', likely to trick users into clicking the embedded links which may lead to phishing pages or malware downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://xajibur.ru/strik?utm_term=physics+equations+of+motion+class+9+questions PDF link annotation
    • http://senteber.site/19284449174ex27r.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4414866/normal_6043104e0a430.pdfIn PDF document text
    • http://feelslike35.com/66747337454o47wf.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450156/normal_5fda3ca5ccfa6.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4480886/normal_5fecc65b142f2.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4423133/normal_601d59163567a.pdfIn PDF document text
    • https://dorikorojuj.weebly.com/uploads/1/3/3/9/133987202/pazarumotekikuted.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4458394/normal_5ffcda71a688f.pdfIn PDF document text
    • https://bekalerobo.weebly.com/uploads/1/3/5/3/135346313/sesojedixum.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383147/normal_602af1b3e2b32.pdfIn PDF document text
    • http://lakcherie.ru/what_does_the_date_on_a_smoke_detector_mean49nh3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4494436/normal_6039f5a2d9205.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4503309/normal_5fc5d89530b3c.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4482020/normal_5ff03f6752bf2.pdfIn PDF document text
    • https://wisapemewe.weebly.com/uploads/1/3/4/7/134713478/8added45.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417413/normal_5fd194b5bd33a.pdfIn PDF document text
    • https://samomalekadoj.weebly.com/uploads/1/3/1/4/131438786/basidadegot-damizeletegoku-vitud.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4449777/normal_601384843ae87.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4489033/normal_5fda1f8f73a11.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://notaruk.rf.gd/biodata_format_with_photo.pdfIn PDF document text
    • http://xalezojo.epizy.com/91047209282.pdfIn PDF document text
    • http://majukukosiw.rf.gd/duet_prime_apk.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010212.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10212 5412 bytes
SHA-256: c760d8e098ba2400673eddcf670d44fe1a0848515d95bc914db5489bcd1a1c03
font_01_sfnt_off00011466.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11466 11228 bytes
SHA-256: bdbeff4733878321288ce73698a4c6d50cab5121578c9cb8a3e2fec0abf5e7f8