Malicious PDF — malware analysis report

Static analysis result for SHA-256 f7d2f1ea194a3a25…

MALICIOUS

PDF

87.5 KB Created: 2021-09-16 17:04:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 7364cfa57ea2312a5166c7a2d4fc82c1 SHA-1: 16db64345cc181c9e752b692d37a9efe76a731a5 SHA-256: f7d2f1ea194a3a25597e0df52aeb19fcd4164fe1aa904bb22f7546fbd32b6fb4
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many external URIs pointing to compromised or disposable hosting. The PDF document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links. The presence of numerous URLs, some on compromised CMS uploads, strongly suggests a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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://crewmak.ru/uplcv?utm_term=autism+reading+comprehension+worksheets+pdf PDF link annotation
    • http://nedvizhimost-v-sharm-el-sheikhe.ru/uploads/files/tedirosezatujugusogap.pdfIn PDF document text
    • https://macroedunet.com/userfiles/file/53971759859.pdfIn PDF document text
    • https://larustt.com/upload/ckfinder/files/99821297800.pdfIn PDF document text
    • http://belniig.by/public/file/91011351977.pdfIn PDF document text
    • https://patidarpalanpur.com/web/k/main_admin/ckfinder/userfiles/files/difusaratulofatogovakeb.pdfIn PDF document text
    • http://ewtch.com/upload/files/39609976326.pdfIn PDF document text
    • http://cuakeobinhduong.com/upload/files/baxotojofogugo.pdfIn PDF document text
    • http://globalfeedindustry.com/upload/files/67931786699.pdfIn PDF document text
    • http://uitvaartverzorgingsindex.nl/images/uploads/wabedokezuva.pdfIn PDF document text
    • http://anais.terminarz.online/kosmetyczka/krakow/files/95155165777.pdfIn PDF document text
    • http://doctour.hu/uploads/ckfinder/userfiles/files/xirivojilifuruvafizuneriw.pdfIn PDF document text
    • https://spencershaulageltd.co.uk/wp-content/plugins/super-forms/uploads/php/files/9fc5466af2bb50d0e01a86ddf5c5ffe8/kiwilibaponaronev.pdfIn PDF document text
    • https://rajnnuhiddje.se/userfiles/file/47351267770.pdfIn PDF document text
    • https://cristalparkhotel.com/ckfinder/userfiles/files/leronibusidej.pdfIn PDF document text
    • http://pololanna.com/user_img/files/32213877758.pdfIn PDF document text
    • http://qlionshousing.ca/userfiles/file/45626622378.pdfIn PDF document text
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/p3v6m4gnr5oskspt4f7d10s472/91742093112.pdfIn PDF document text
    • http://bm-shower.com/userfiles/files/jejejip.pdfIn PDF document text
    • http://ellenia3.eu/userfiles/files/16014140148.pdfIn PDF document text
    • http://www.patricktennis.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16140d65e76de7---xonavoz.pdfIn PDF document text
    • https://www.cifphosteleriayturismo.es/ckfinder/userfiles/files/12453226333.pdfIn PDF document text
    • http://www.magicapro.it/wp-content/plugins/formcraft/file-upload/server/content/files/16143282960986---vomevokevijig.pdfIn PDF document text
    • http://dobre-jaja.com/Upload/file/4895425786.pdfIn PDF document text
    • http://mayepnuocmia.vn/data/ckfinder/files/gadutafoxereti.pdfIn PDF document text
    • https://gift-edu.ru/wp-content/plugins/super-forms/uploads/php/files/e0cc4c8a82bec99d60f3b3791d98f9d8/winazagilukititu.pdfIn PDF document text
    • https://jatransfer.com/userfiles/file/pesapakexesaranubupimev.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_off0000f260.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF260 16696 bytes
SHA-256: 4e2014f2e202a351e179f05bcdf28022aac12e85fcf226c8984a2b8d117bd195
font_01_sfnt_off00011d61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D61 11280 bytes
SHA-256: 166a4480bc4235e1becb895cbb20df449580b6367bd01e15ffef0bffa80fdbc4
font_02_sfnt_off00013791.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13791 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1