Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9fb432717e447d7…

MALICIOUS

PDF

92.8 KB Created: 2021-09-17 19:00:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 6ecd9f5d169161b11b0c0a7c4b722d72 SHA-1: 52c9b3923b6bacaef3b1c1a2a3fb0b8ffbe19797 SHA-256: b9fb432717e447d775a60cecd1c618b86233e4ccf596cbc2e12269a09ab00516
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or domains commonly used for hosting malicious content. Heuristics indicate this is a link farm designed to direct users to potentially harmful sites, consistent with phishing or malware distribution lures. The ML classifier and ClamAV detection strongly suggest malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://inwebjor.ru/uplcv?utm_term=android+kamera+depan+flash+murah PDF link annotation
    • http://lukoilmarine.com/ckfinder/userfiles/files/xavefepalib.pdfIn PDF document text
    • https://themodernla.com/wp-content/plugins/super-forms/uploads/php/files/ab95a6178d5cedf6068a0b93bcc8ac4a/73355249727.pdfIn PDF document text
    • https://unovosti.tv/ckfinder/userfiles/files/51331727125.pdfIn PDF document text
    • http://deeringbayrealestate.com/userfiles/files/toboravosom.pdfIn PDF document text
    • http://sinostandards.net/upload/files/58334464589.pdfIn PDF document text
    • http://www.dfdtrading.sk/ckfinder/userfiles/files/fizevowovux.pdfIn PDF document text
    • http://childconnect.com/swi/fckfiles/file/88412272494.pdfIn PDF document text
    • http://assotechne.eu/userfiles/files/31308336999.pdfIn PDF document text
    • http://opt-russtd.ru/data_center/upload_pictures/file/85249965237.pdfIn PDF document text
    • https://westhigienia.hu/editor_up/besuxafufopifebozul.pdfIn PDF document text
    • http://starwindows.ie/ckfinder/userfiles/files/69441080596.pdfIn PDF document text
    • http://ph-easycome.com/userfiles/file/kobovamevulaguna.pdfIn PDF document text
    • https://www.domosystem.gr/ckfinder/userfiles/files/47701994636.pdfIn PDF document text
    • http://sandlnae.com/data/editor/file/bopevajag.pdfIn PDF document text
    • http://www.humillacionyestrella.org/ckfinder/userfiles/files/doxefefoburuzitaga.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/161370e8b7c548---45415609574.pdfIn PDF document text
    • http://recrute.fr/files/files/nanimoxorekule.pdfIn PDF document text
    • http://gospelpour100voix.com/fichiers/newsletter/file/zugudixanixa.pdfIn PDF document text
    • http://ichieh.tw/uploads/files/202109081500307443.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/740kvd71pu3errj3d100r6rju4/71128699106.pdfIn PDF document text
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16135908db4f91---12394075074.pdfIn PDF document text
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/4d9d7be69ee4b08ac79a2f2ee29135c8/wufenibusuxojiduzalipefoz.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_off00010444.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10444 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011c5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C5B 10840 bytes
SHA-256: 5ad655139daa4e52ff970285f9ef8678e0caf3993d98c9e9ba62a941b676695e
font_02_sfnt_off0001351c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1351C 18340 bytes
SHA-256: 533b9968aa0cf8778707a9c3917b69b0d739bc326941278e2d6ceff8ff2ed753