Malicious PDF — malware analysis report

Static analysis result for SHA-256 7945b98fae30fe23…

MALICIOUS

PDF

77.5 KB Created: 2021-03-14 15:14:02 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-02
MD5: 6fc11ab539db9cc02acf40bb769fbd2c SHA-1: 31646b80db67ccb3faa6268b3cf3d162d5528d8d SHA-256: 7945b98fae30fe23054c314db0d2ba3eebf2ff1b283cd10b0b9931b7c93b3fb9
186 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains a large number of external links, many pointing to disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The document body, though heavily obfuscated, appears to be related to English language exercises, serving as a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://resalured.ru/award?keyword=past+simple+past+continuous+past+perfect+exercises+intermediate+pdf PDF link annotation
    • http://pobunav.sportsontheweb.net/loloxot.pdfIn PDF document text
    • https://niwonuruvi.weebly.com/uploads/1/3/4/7/134767359/dufinukefigubal-ponulepavizawap.pdfIn PDF document text
    • http://jisetatiloro.scienceontheweb.net/what_does_the_term_blue_falcon_mean.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4423428/normal_5ff6162267285.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4479923/normal_5fcd72d552938.pdfIn PDF document text
    • http://tebeririz.scienceontheweb.net/keluxetewi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4375507/normal_601591adbe9e0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4427300/normal_603dea9ebe28b.pdfIn PDF document text
    • https://kaxamutibe.weebly.com/uploads/1/3/5/3/135348628/fuduzafesuva-xibapesotinara-neziwufite.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://5bf49506-6ef1-42f8-8f90-7e3689255fd3.filesusr.com/ugd/8fe1bf_229dae6ba80749fe86a343869e133796.pdf?index=trueIn PDF document text
    • https://d3826037-6016-486c-99e9-dc41bc666644.filesusr.com/ugd/b81754_3915bd9b71ae4baca0cb1715f06f9e0f.pdf?index=trueIn PDF document text
    • https://8f1c0ae7-1ba6-4c51-a623-4d29f5e3aebb.filesusr.com/ugd/c1615c_d4701752b500485992fa2088db13be6d.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/ab3ed117-bd5f-4321-805e-f14d40e3490b/46649996102.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/48e443ab-6c1f-4239-95c5-9728a217c85d/vabebitetefovikivalebogiw.pdfIn PDF document text
    • http://nerezusilanake.atwebpages.com/99989982258.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/97f80972-3d9d-4a85-821a-61cdbcc98bac/1269267189.pdfIn PDF document text
    • http://pikubub.onlinewebshop.net/how_to_cook_rice_in_the_electric_pressure_cooker.pdfIn PDF document text
    • http://zizenatoxu.myartsonline.com/jixufajopakulowujorevakem.pdfIn PDF document text
    • https://336ddc11-c37d-4cd6-9685-7accad2975f7.filesusr.com/ugd/479fa9_c2c388771f7c4db9bb36e2ef9573e143.pdf?index=trueIn PDF document text
    • http://lawesiwewif.onlinewebshop.net/29600702361.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_off0000f2ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2CE 5372 bytes
SHA-256: 2d44c807f7e2a353967926f22ce77a99d102f74e2ecd9c593b4b3657ff803160
font_01_sfnt_off000104ff.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104FF 10344 bytes
SHA-256: 6c17381bda3b048542a78e7e6c518efc004067a7ba2f118e601989865e76e07d