Malicious PDF — malware analysis report

Static analysis result for SHA-256 53612216d86d8693…

MALICIOUS

PDF

83.5 KB Created: 2021-09-23 11:56:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: b3985fcf1d00541bd5504c6c92c9d837 SHA-1: 71f6de12a40deed80aa22cd865bd82df789a590b SHA-256: 53612216d86d86934dc8f18e8e6decdbbce1395daf44ad6f8728b6ba1f9d72a6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm, with multiple URLs pointing to potentially compromised websites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. While no scripts were directly extracted, the structure suggests it's designed to lure users to external malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://sandsflooring.co.uk/ckfinder/userfiles/files/kitek.pdf In PDF document text
    • http://benrassam.com/uploads/files/79569224037.pdfIn PDF document text
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ec5017f2c2---vafebuv.pdfIn PDF document text
    • http://www.smpnuenen.nl/images/files/xotakipuwujag.pdfIn PDF document text
    • http://work4shop.cz/userfiles/file/nukofapigivilinejirowod.pdfIn PDF document text
    • http://musikpark-live.de/userfiles/file/16983812452.pdfIn PDF document text
    • https://concurs-euclid.ro/upload/fck/rozurelipuxu.pdfIn PDF document text
    • http://thailaundry.com/imgUpload/files/ridugelosifubus.pdfIn PDF document text
    • http://www.marcelasemper.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131882f04c98---58509529378.pdfIn PDF document text
    • http://italianopizzeria-pg.com/uploads/files/lezugagizabobuwub.pdfIn PDF document text
    • http://rgn2u.com/userfiles/files/24559002966.pdfIn PDF document text
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/i6pf2gl2gqnbljg41cndo140ff/favawugoguzovogimizeb.pdfIn PDF document text
    • http://dienlanhhuubinh.com/upload/files/selatubebirofukelufegite.pdfIn PDF document text
    • http://parzenica-bialka.pl/userfiles/files/44234662548.pdfIn PDF document text
    • http://paraleumarian.ro/app/webroot/files/userfiles/files/30759099633.pdfIn PDF document text
    • http://kiiga.ru/userfiles/file/kewosumerunolog.pdfIn PDF document text
    • https://shih-tzu.ro/files/file/89629653876.pdfIn PDF document text
    • https://www.tifdip.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613be0caa0a74---junedapus.pdfIn PDF document text
    • http://zoldjogsi.hu/uploads/files/6747679275.pdfIn PDF document text
    • http://szakkepzosiklos.hu/upload/file/84387895508.pdfIn PDF document text
    • http://emilygrilltogo.com/uploads/files/94507746378.pdfIn PDF document text
    • https://fiberglasssupplydepot.com/userfiles/files/sitidugevi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=watch+rupaul%27s+drag+race+all+stars+6+onlinePDF 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_off0000db97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB97 19452 bytes
SHA-256: bba5a7ca81106ccfe0b81ec9d85c06ebe7d2a7b07028116ed8c04908fcf5a434
font_01_sfnt_off00010e2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E2F 11088 bytes
SHA-256: 784930f9a2beedd00ff8c2e63676f1f7a4aa75902123eecc643c3b10a077f518
font_02_sfnt_off000127de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127DE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1