Malicious PDF — malware analysis report

Static analysis result for SHA-256 df21cd57eeec25c0…

MALICIOUS

PDF

69.2 KB Created: 2021-09-26 11:52:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 71bf12c787bb2dc0d799b34f387a8ac6 SHA-1: 120f957dc8ac6f614e9586e3886fed8aefd3d447 SHA-256: df21cd57eeec25c0debd2870a983f80426d3fd68af18d27e9411d0395a1fc35c
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and a significant number of external URIs, many of which are hosted on compromised WordPress sites or disposable domains, forming a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware delivery through these redirect links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://crewmak.ru/uplcv?utm_term=best+proxy+app+for+android PDF link annotation
    • https://messianic.live/wp-content/plugins/super-forms/uploads/php/files/f9c3dc6012f5e6a72f3406db51c7b47d/68348303524.pdfIn PDF document text
    • http://ciela13.leaddeehub.com/userfiles/files/930654699.pdfIn PDF document text
    • https://zaragozadenoche.es/upload/files/35946786801.pdfIn PDF document text
    • https://angkalaris.com/contents/files/giniwewusijafoduli.pdfIn PDF document text
    • http://cgpreceptor.com/ckfinder/userfiles/files/22918110194.pdfIn PDF document text
    • http://kme-kme.cz/files/file/69190500828.pdfIn PDF document text
    • http://langmoon.jp/js/upload/files/sebipemoworewugenugapi.pdfIn PDF document text
    • http://patchworkstudio.de/userfiles/file/texujizomaxazorejefu.pdfIn PDF document text
    • https://www.aledrukujemy.pl/ckfinder/userfiles/files/82338700611.pdfIn PDF document text
    • http://shippingengineering.com/files/ckeditorothers/rapuvuduxozame.pdfIn PDF document text
    • http://uts.edu.co/portal/app/ckfinder/userfiles/files/65458559610.pdfIn PDF document text
    • http://www.frank-diagn.hu/userfiles/files/jeraduz.pdfIn PDF document text
    • http://mywymc.com/userfiles/file/xujuluridijipuje.pdfIn PDF document text
    • http://hmondo.com/userData/board/file/55385064549.pdfIn PDF document text
    • https://7mark3t2-7aya.com/contents/files/18417360142.pdfIn PDF document text
    • http://mariekevanvlierden.nl/survey/userfiles/files/36980038618.pdfIn PDF document text
    • https://sunridgecorp.com/uploads/files/202109240417103064.pdfIn PDF document text
    • https://www.seblocation.com/ckfinder/userfiles/files/vipawut.pdfIn PDF document text
    • https://polinagerz.ru/wp-content/plugins/super-forms/uploads/php/files/9jnkgvegihdpt16bi2q94rvb9d/kavavis.pdfIn PDF document text
    • https://www.davidwoodpersonnel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16149063714acb---wedoxa.pdfIn PDF document text
    • http://sinara.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/16133ed5dbf87e---40450383241.pdfIn PDF document text
    • http://ne-moloko.ee/wp-content/plugins/super-forms/uploads/php/files/b2aaab870f56820e48ed31682a3ec586/vuzimu.pdfIn PDF document text
    • https://triatlonshop.cz/userfiles/file/foxigowase.pdfIn PDF document text
    • http://thevalleytrader.com/files/ririzilufidit.pdfIn PDF document text
    • https://migger.dk/userimages/file/80426143116.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://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_off0000b023.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB023 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c835.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC835 15396 bytes
SHA-256: 76a77a31c4fcea1bbb71b5136e3b42d2aa14147310b90301d4937a827ccd2bcd
font_02_sfnt_off0000ee98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE98 10716 bytes
SHA-256: 3e91caf6a4f50695efcc3df4bd3a982d97c6c99fb6fd1adbfb87259e3a8147f0