Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b36769788e8c222…

MALICIOUS

PDF

79.5 KB Created: 2021-09-11 07:11:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: e1e78b27ca57cae3a5d95c46c226547a SHA-1: 203be9adbef7418fc1c6e1ad2f476a1dc4cc69f4 SHA-256: 5b36769788e8c22258197c91f7e29c65bc168a15a14c32a6f6f7c86fa587dc9d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The ML classifier and ClamAV detection strongly indicate malicious intent. The PDF contains numerous embedded URLs pointing to various domains, many of which are likely part of a link farm designed to obscure the ultimate destination. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests a tactic to evade detection by distributing links across many disposable hosts. No scripts were extracted from this sample, but the overall structure and URL distribution point towards a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 5

  • 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 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://estoniapools.com/contents/files/bakusosowomivefasuvedamiv.pdf In PDF document text
    • http://dostrojar.sk/UserFiles/file/noboju.pdfIn PDF document text
    • http://jysfh.com/upload_fck/file/2021-9-4/20210904015014307119.pdfIn PDF document text
    • https://egyediajandekotletek.hu/mvc/userfiles/file/39194089212.pdfIn PDF document text
    • http://radecznica.pl/userfiles/file/sovamufewatipabolofil.pdfIn PDF document text
    • http://ozdermusavirlik.net/userfiles/file/77016551749.pdfIn PDF document text
    • https://h1t-urlaurora1-turbo.com/contents/files/lusabewitujibez.pdfIn PDF document text
    • http://baove24h.info/upload/files/balubukabinafed.pdfIn PDF document text
    • https://mehfermobilsaglik.com/userfiles/file/mevav.pdfIn PDF document text
    • https://ptogel2.com/contents/files/73264900913.pdfIn PDF document text
    • http://bielle-srl.com/userfiles/files/vutovet.pdfIn PDF document text
    • http://biondiairsystem.it/userfiles/files/varaselagobevomenirekado.pdfIn PDF document text
    • http://chenruichem.com/upload/files/deduwu.pdfIn PDF document text
    • http://xn--42-jlclgg6a3e.xn--p1ai/userfiles/file/bijegirumuxewejamu.pdfIn PDF document text
    • http://aci-immobilier-douai.fr/userfiles/files/zabevebari.pdfIn PDF document text
    • https://gedayapi.com/userfiles/file/4855271405.pdfIn PDF document text
    • http://aan.kz/ckfinder/userfiles/files/84094743565.pdfIn PDF document text
    • http://xedaptheduc.net/app/webroot/uploads/files/74354981982.pdfIn PDF document text
    • http://hunicorn.hu/userfiles/file/zamefimo.pdfIn PDF document text
    • https://xlux.vn/wp-content/plugins/super-forms/uploads/php/files/vu0l6mlbe4np9s6knmd8kpd0tb/zojivurigafexi.pdfIn PDF document text
    • https://elger.cz/fckphotos/file/niveruxubinatuxusobo.pdfIn PDF document text
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/648653da5e08197fd1e77f61d0662534/zuwemowodo.pdfIn PDF document text
    • http://thedewakohchang.com/image/upload/File/isegu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=how+to+set+wallpaper+to+fit+screen+androidPDF link annotation
    • 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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d452.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD452 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ec69.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC69 10688 bytes
SHA-256: ed8bc034f13eb0d80f1c5a73a200ec31660a138b055e766aa8d957a4971670e0
font_02_sfnt_off0001050d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1050D 16828 bytes
SHA-256: e12929d295cac94e95b7df67872008e939211e43fb4f11a0b252acac2a56725b