Malicious PDF — malware analysis report

Static analysis result for SHA-256 40c35b3c6040ca85…

MALICIOUS

PDF

81.3 KB Created: 2021-04-10 18:50:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 6c60f6366da9b54e686c1a5722caa832 SHA-1: 23aa420363d637c0ad5f3305cc86740583237e83 SHA-256: 40c35b3c6040ca856798c0598513ece13c00aa90949a3c46ddb3e98eda22e90f
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains a large number of external links, many hosted on disposable domains, suggesting a link farm designed to direct users to potentially harmful content. The document body, though partially corrupted, suggests a lure related to argumentative essays, which is likely a pretext to mask the malicious nature of the embedded URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://jacksth.ru/strik?utm_term=ejemplo+de+un+ensayo+argumentativo+corto+con+sus+partes PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4384164/normal_5ff8b6e2349e0.pdfIn PDF document text
    • https://tadodilupusoje.weebly.com/uploads/1/3/4/7/134702012/sokorab_lekirafobij_xupaziwef.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4495536/normal_605a73ad118d8.pdfIn PDF document text
    • https://rezigetofetima.weebly.com/uploads/1/3/1/1/131163738/3e65b.pdfIn PDF document text
    • http://detonic-hypertonie.website/how_to_explain_the_balance_sheetc8tw3.pdfIn PDF document text
    • http://xekumaluvox.iblogger.org/86417824148.pdfIn PDF document text
    • http://poradoit1.site/975765711507ul18.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366048/normal_60438bdb20054.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470019/normal_6047f131e5968.pdfIn PDF document text
    • https://jaloteke.weebly.com/uploads/1/3/4/0/134096083/wowumilorativ_tuxidid_neratapatod_ligomavun.pdfIn PDF document text
    • https://kitabenulo.weebly.com/uploads/1/3/0/9/130969432/walawojifekojog.pdfIn PDF document text
    • https://fumabufoduf.weebly.com/uploads/1/3/5/3/135313851/timonujesusokepit.pdfIn PDF document text
    • http://zagafesujed.iblogger.org/jumaj.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4465930/normal_602e269bc388f.pdfIn PDF document text
    • http://merutakozuxonu.22web.org/92783269831.pdfIn PDF document text
    • https://vugogirofezufus.weebly.com/uploads/1/3/4/3/134355312/bofikowubiselox.pdfIn PDF document text
    • http://checkmyscore.info/where_can_i_write_a_review_on_a_restaurantjukdk.pdfIn PDF document text
    • https://cdn.sqhk.co/midipijikami/jbGMjaa/xegekexeligomijivi.pdfIn PDF document text
    • https://cdn.sqhk.co/jirudumom/jwhjher/95483579322.pdfIn PDF document text
    • https://besusawoses.weebly.com/uploads/1/3/5/3/135318815/6984e650b5d8.pdfIn PDF document text
    • https://cdn.sqhk.co/xosaletozobi/S6jc4ji/hubspot_agency_certification_answers.pdfIn PDF document text
    • https://rezisepadas.weebly.com/uploads/1/3/4/2/134235668/gozazilosivepozevi.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://wuxuxumeso.rf.gd/biot_savart_law_derivation_equation.pdfIn PDF document text
    • http://setowibuvi.epizy.com/85247165723.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_off0000fad8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAD8 5588 bytes
SHA-256: bfc500bdf7d2789a6d63f78b724920b8c918bfc9375f6a1a388e49c82f026f37
font_01_sfnt_off00010dd6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DD6 12152 bytes
SHA-256: 7bfca54c040ca3f7c3f425193871d0e8013f280f8cbabde6b5629400b732a3cf