Malicious PDF — malware analysis report

Static analysis result for SHA-256 f1621f842df1cde1…

MALICIOUS

PDF

90.5 KB Created: 2021-09-01 18:08:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 092fb9488d461ce4e995a9a57ee6bc1a SHA-1: 409cbecb713223f5b8b3f669b60ed13a14b9f528 SHA-256: f1621f842df1cde13d693d8a0a6714cd414e782a7d65b867da113fa761331b23
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many hosted on compromised WordPress sites or disposable domains, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, further obscuring its true intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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
  • 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 https://viettincapital.vn/upload/files/78813977386.pdf
    • https://metroguards.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607577c8b9088---kidopijixa.pdf
    • https://samajsutra.com/userfiles/files/retilusatujunuterutamu.pdf
    • https://carstenrath.com/wp-content/plugins/super-forms/uploads/php/files/bcn8oacv01cmbn8n5caiv6beds/17983897811.pdf
    • http://animalscipublisher.com/files/upfiles/file/85963117181.pdf
    • https://refour.dk/wp-content/plugins/super-forms/uploads/php/files/497b967d807e6fcb31e5d16047104bfc/natovatumojigixopa.pdf
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/tdmgp3ac7cbbn6a6bcviofl25e/dizopuvetukagomaxem.pdf
    • http://photopuzzle.net/userData/board/file/98503977951.pdf
    • http://aodaiminhhanh.com/app/webroot/uploads/files/zuxexulemalategozamujoki.pdf
    • http://nguyenxuanhuong.com/upload/files/zepifejixipudekatuvif.pdf
    • https://hsse.cl/files/xofatonazokudij.pdf
    • https://www.simcoerecovery.net/wp-content/plugins/super-forms/uploads/php/files/fa4q26habotr1p2edlas77esia/guwopigedev.pdf
    • https://urbanplace.me/wp-content/plugins/super-forms/uploads/php/files/c2b337fd1eb514c11cda881683748b30/kexojuvekoxotekagug.pdf
    • http://boathousebrokerage.com/userfiles/file/79851434188.pdf
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609dbad10af5b---favipijopuniwoz.pdf
    • https://dipinkrishna.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085681ebe4fc---wixesefumufimovoza.pdf
    • http://www.premiumimport.nl/ckfinder/userfiles/files/gepomutigu.pdf
    • https://homini.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16080617dab039---mifilu.pdf
    • https://led7.ru/file/daxivofexin.pdf
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/16087ff0b59912---20620204238.pdf
    • https://capitaleny.com/wp-content/plugins/super-forms/uploads/php/files/ad2eed46f1f8b18852919ebe54bf4d3b/givigefojiwetugaso.pdf
    • http://radio-salsa.com/php/rs/filesupload/file/guvamirejigunujepi.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=small+boils+on+face
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fe48.bin
89c20703df16698368e0c3e443be3ed79d7363c82bb477b19b765cd3722f58c1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFE48 10516 bytes
font_01_sfnt_off00011629.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11629 16792 bytes
font_02_sfnt_off00012e3b.bin
fbab1a1dba8ad289960e8b46a6ec3a5ff3fcb8c45242e2032a91c18716660c11
pdf-font-stream PDF embedded font (sfnt) at offset 0x12E3B 17616 bytes