Malicious PDF — malware analysis report

Static analysis result for SHA-256 8a65120d3a849d72…

MALICIOUS

PDF

83.4 KB Created: 2021-09-23 22:15:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: a7ec986dd48702d5ef071b307130649c SHA-1: d5fe0c9c5b605e48f9be134a66d1f31add9c75f9 SHA-256: 8a65120d3a849d727a3c90967442dbc45f4061c3f5b2b10a082ea7ebee3aa37c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier indicating maliciousness. The presence of numerous embedded URLs, many pointing to disposable domains and link farms, strongly suggests a phishing or malware distribution campaign. The document body, though heavily obfuscated, contains metadata indicating it was generated by wkhtmltopdf, a tool often used to create malicious PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://inwebjor.ru/uplcv?utm_term=how+to+download+alarm+tones+for+android PDF link annotation
    • http://artospace.com/pics/file/61239552680.pdfIn PDF document text
    • http://www.udelimpa.es/ckfinder/userfiles/files/deruwitujinireveg.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/161397f3ebe182---lijuvo.pdfIn PDF document text
    • https://bawwabatrizq.com/userfiles/file/48099358662.pdfIn PDF document text
    • http://likuidart.com/files/ckeditor/files/88398077658.pdfIn PDF document text
    • http://xz-brand.com/ckfinder/userfiles/files/xuxogibupidobejiposafab.pdfIn PDF document text
    • https://dalton-english.com/userfiles/file/68164798734.pdfIn PDF document text
    • http://helderlive.nl/ckfinder/userfiles/files/wimonibezanuxox.pdfIn PDF document text
    • https://hotelexpert.ro/uploads/files/99223839130.pdfIn PDF document text
    • https://billard-hauri.ch/userfiles/file/xetekagobabi.pdfIn PDF document text
    • https://pima-alarms.eu/slicice/file/42923007187.pdfIn PDF document text
    • https://buka.ru/sadm_files/21663792989.pdfIn PDF document text
    • http://www.dawnrotaryclub.tw/UserFiles/files/72011774548.pdfIn PDF document text
    • http://chistogood.ru/admin/ckfinder/userfiles/files/17599073354.pdfIn PDF document text
    • http://samocvet.org/foto/ck/files/95251815508.pdfIn PDF document text
    • http://dragonera.cn/admin/userfiles/file/wotorinuvafizipogezo.pdfIn PDF document text
    • http://ugyvednok.hu/userfiles/file/90649063531.pdfIn PDF document text
    • https://www.speeddating.lt/speeddating/ckfinder/userfiles/files/jejoraduzowevonevuz.pdfIn PDF document text
    • https://service-panev.com/userfiles/91771830532.pdfIn PDF document text
    • https://transturist.ba/ckeditor/ckfinder/files/files/nafevazowagasomek.pdfIn PDF document text
    • http://accessibilite-salle-eau.com/ckfinder/userfiles/files/doradarupam.pdfIn PDF document text
    • http://bbpcosmetics.com/admin/upFiles/2021-9/file/dopat.pdfIn PDF document text
    • https://poulinstrapscan.com/userfiles/file/loxajatedetapopeso.pdfIn PDF document text
    • https://otomatcilarmetal.com/otomat/upload/files/gujawuxuvemumijik.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/16130563f568ad---filozuk.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_off0000e041.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE041 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f853.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF853 18240 bytes
SHA-256: 9308d9657942c0d9d111ca8d9f88cdd51ef89ffd0aa34bd43b1d2b3e5748a08c
font_02_sfnt_off00012744.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12744 10592 bytes
SHA-256: 968d9b60edcac4bb78020ae6da97882e8d0ed72e1790f021d14010df60913a0d