Malicious PDF — malware analysis report

Static analysis result for SHA-256 6c4b218b77694326…

MALICIOUS

PDF

96.1 KB Created: 2021-09-16 19:41:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 21de72660c36961c6c6d11cafa1bd2fe SHA-1: b891bb00ac09bc14b2e4dc9ee9ce91f6f9994d20 SHA-256: 6c4b218b776943265cc97d502c1e306f2a6876aa9484ea384a518409d31816ee
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised or disposable hosting. The ML classifier strongly indicated maliciousness, and the heuristics identified it as a link farm, suggesting a phishing or SEO manipulation scheme. No scripts were extracted, limiting the analysis of direct payload execution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 5

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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 http://polishingmarblefloor.it/userfiles/files/81835740684.pdf In PDF document text
    • https://eagleegg5k.com/ckfinder/triplebuserfiles/file/tebinafapoz.pdfIn PDF document text
    • http://taiwangallant.com/uploads/files/202109140412376152.pdfIn PDF document text
    • http://hgbs.de/userfiles/file/54874382081.pdfIn PDF document text
    • http://tischlerei-schlusche.de/sites/default/files/file/96817560819.pdfIn PDF document text
    • https://www.pirkitpadangas.lt/ckfinder/userfiles/files/gumowu.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/ccccdc26e84911cf263a89559e91d6ce/dezezikijowejixawib.pdfIn PDF document text
    • http://samurairamenbar.com/uploads/files/48421167290.pdfIn PDF document text
    • http://theofficefurniturestore.com/ckfinder/userfiles/files/pugejivavagolojato.pdfIn PDF document text
    • http://skncn.com/u/files/pulefixuni.pdfIn PDF document text
    • http://msnladyboy.com/ckfinder/userfiles/files/5092124227.pdfIn PDF document text
    • http://thayloilocnuoctaihanoi.net/upload/files/pusakijutojivuw.pdfIn PDF document text
    • https://sunarchegypt.com/userfiles/file/guwuzazilu.pdfIn PDF document text
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/161301ce28e380---rakixijadaravozi.pdfIn PDF document text
    • https://inprovitperu.com/ckfinder/userfiles/files/5146730542.pdfIn PDF document text
    • http://daithanhnam.com/upload/files/6113617088.pdfIn PDF document text
    • http://yilip.net/userData/board/file/rozetoge.pdfIn PDF document text
    • https://humantouchtranslations.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/16140cf1726e09---63756880253.pdfIn PDF document text
    • https://clinicaabrahaoosta.com.br/ckfinder/userfiles/files/76191659885.pdfIn PDF document text
    • https://orsam.org.tr/paketler/ckfinder/dosyalar/files/dabonuwa.pdfIn PDF document text
    • https://ietc-oman.com/userfiles/files/74206245370.pdfIn PDF document text
    • https://lighthousemacau.com/html_upload/file/donuweromeb.pdfIn PDF document text
    • https://thefencedocumentary.ca/adminfiles/file/78912686712.pdfIn PDF document text
    • https://yuktogel.com/contents/files/sagixenivezofitiperamoni.pdfIn PDF document text
    • https://inprovitargentina.com/ckfinder/userfiles/files/56039871370.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=how+to+see+someone%27s+instagram+followers+without+following+themPDF 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_off00011103.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11103 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012915.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12915 18416 bytes
SHA-256: ddf4e9119cf52fc59766831a2b373d413f006000a2f4845816e761975e01f1b3
font_02_sfnt_off000158fc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x158FC 10872 bytes
SHA-256: df53b597a8df32e0d3651fa9c4ab11466628a4c19bcb52072ce5b9b8b6104f94