Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8095786221d3a11…

MALICIOUS

PDF

69.6 KB Created: 2021-09-25 02:04:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 1fc1652f57f6854cf8b3adbe76f83dc8 SHA-1: 8f5f6adf92f3829f4ef91b38b6ebd672e756eba8 SHA-256: b8095786221d3a11cfb81fe2b2ecd02450d5ff606f704337c920a3169eefa882
156 Risk Score

Malware Insights

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

The file is a PDF containing numerous embedded URLs, many of which point to disposable hosting or compromised CMS upload directories, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, and the document body was unreadable, so the rationale is based on the URL analysis and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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://oniceh.ru/uplcv?utm_term=android+body+type+women PDF link annotation
    • http://quaisetoiles.fr/img_pages/file/pulolusat.pdfIn PDF document text
    • http://tkhomedeco.com/assets/uploads/ckedit/files/20210913211456.pdfIn PDF document text
    • http://vititanon.com/user_img/files/nopuxarilijevufivixewofa.pdfIn PDF document text
    • https://study-abroad-travel.com/ckfinder/userfiles/file/loxajewupolenudi.pdfIn PDF document text
    • https://sitycare.com/FCK-UserFiles/files/reziwozekew.pdfIn PDF document text
    • http://tochuchoinghi.org/files/65927225575.pdfIn PDF document text
    • https://dialogueinpraxis.net/files/docs/26534474312.pdfIn PDF document text
    • http://eegbiofeedback-leszno.pl/userfiles/file/soraxiduxezagugawud.pdfIn PDF document text
    • http://geometrabottero.it/userfiles/files/84208249636.pdfIn PDF document text
    • https://middletonchambers.com/ckfinder/userfiles/files/34633963323.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/854b8adea83c14434558eb87b7ac06c8/pumorov.pdfIn PDF document text
    • https://bdata.vn/upload/files/87864323947.pdfIn PDF document text
    • https://pastravariaizvoarelebratiei.ro/images/file/80439386026.pdfIn PDF document text
    • https://ethnicminorities.heephong.org/ethnicminorities/cmsadmin/ckfinder/files/69045076818.pdfIn PDF document text
    • http://expertworker.paraleumarian.ro/app/webroot/files/userfiles/files/biviwadikutejofigogep.pdfIn PDF document text
    • https://rhuyscampingcar.fr/images/files/xaxisexuz.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/l4e88drnt3eqnocq9u3fvma881/vubuvuwuxal.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140871c52f43---bokegisamunugereputez.pdfIn PDF document text
    • https://francoisdaulte.com/ckfinder/userfiles/files/5537796585.pdfIn PDF document text
    • https://cancelaria.pl/galeria/file/66476417495.pdfIn PDF document text
    • https://sooryasales.com/uploads/file/gowobemaregogarolerisiwoj.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_off0000aef0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAEF0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c707.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC707 10496 bytes
SHA-256: 4dd4f49373e6a877b7f75bfe8bd263ba81076367f9b384e7817d0ca22c6f8cbf
font_02_sfnt_off0000deb4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEB4 16080 bytes
SHA-256: ad83ab2aff141734c435cbd1c56806e3938d913a0a5aa1faf7024f60c0f00d28