Malicious PDF — malware analysis report

Static analysis result for SHA-256 523e687ae18a458c…

MALICIOUS

PDF

117.8 KB Created: 2021-05-23 22:59:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 911b15f657d3953e5be23ed8543b2d39 SHA-1: e3ae3f5e02d4343c0be2d00304a7f318d8882229 SHA-256: 523e687ae18a458c14d26a42a409bc75486c5134b60ee1037adb10cb45c4bc4c
186 Risk Score

Malware Insights

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

The PDF document was identified as malicious by ClamAV and an ML classifier, exhibiting characteristics of a link farm with numerous external URLs. The presence of a link farm suggests an attempt to distribute malicious content or engage in phishing by directing users to potentially harmful websites. No scripts were extracted, but the overall structure and URL distribution indicate a malicious intent.

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://leonvi.ru/strik?utm_term=big+sky+big+money+pbs+frontline+worksheet+answers PDF link annotation
    • https://govonomuvilikiw.weebly.com/uploads/1/3/4/6/134620083/juwuvudag.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387581/normal_60640d344c57c.pdfIn PDF document text
    • https://fezuwarojeti.weebly.com/uploads/1/3/1/3/131383544/8927154.pdfIn PDF document text
    • https://bopifodefow.weebly.com/uploads/1/3/4/3/134383970/2304c3432c425.pdfIn PDF document text
    • https://zawoluzowusemad.weebly.com/uploads/1/3/4/6/134697528/susukuwubelugeg-fegukewokiw.pdfIn PDF document text
    • https://kajimawujejava.weebly.com/uploads/1/3/5/3/135348493/516115.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4412757/normal_5fca7bc10d544.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4411218/normal_6017fc56c4d78.pdfIn PDF document text
    • https://tevoletefe.weebly.com/uploads/1/3/1/6/131606261/5531275.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4403534/normal_5ffd1afccad4a.pdfIn PDF document text
    • https://buvawaxeve.weebly.com/uploads/1/3/0/8/130874113/7314550.pdfIn PDF document text
    • https://gojupisot.weebly.com/uploads/1/3/4/0/134016698/xipevupifinu.pdfIn PDF document text
    • https://sosuxivi.weebly.com/uploads/1/3/6/0/136056733/sapome.pdfIn PDF document text
    • https://wekopigigosem.weebly.com/uploads/1/3/4/5/134503853/3b4b1.pdfIn PDF document text
    • https://fuzewejobedogu.weebly.com/uploads/1/3/1/4/131482867/jibufizosixunal.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403413/normal_601fee0541b16.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/8da3fb64-cfc2-4bbc-baea-f013d2eed902/graphic_design_courses_institute_in_pune.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/86eade4c-1cd9-4871-8241-70e3c833587d/english_grammar_exercises_tenses_intermediate.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/99e6a311-5a57-4d02-89ef-6c8e3a0f4a08/34436548026.pdfIn PDF document text
    • https://s3.amazonaws.com/vaxebisapesi/83945977619.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/82d86486-e3f7-4fcd-8326-f1c97725844b/40012509222.pdfIn PDF document text
    • https://s3.amazonaws.com/mavixu/5th_grade_go_math_book_answer_key.pdfIn PDF document text
    • https://s3.amazonaws.com/lewuli/nudipabotorod.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_off00018f6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18F6B 5760 bytes
SHA-256: a41eb6d5881e132e257bdec07c13e3e4ed81cc8904c4352012adbe67ab73d4e5
font_01_sfnt_off0001a301.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A301 11208 bytes
SHA-256: 1ade54a97b7e558504d231371bcaf8855f118f2462a3ab0f8bcbac8e271b62dc