Malicious PDF — malware analysis report

Static analysis result for SHA-256 3d51bb0b0401c0f9…

MALICIOUS

PDF

85.0 KB Created: 2021-07-15 19:32:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: cde554d525f2d7a743ecb2fcc66d24db SHA-1: 9db4515f28fd43cadc2f71b592bb65407f7ca160 SHA-256: 3d51bb0b0401c0f98b216f4c65a8baaca67f89fd49d08f6f60264c3560cc9d3c
156 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier indicating a high probability of maliciousness. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites and disposable hosting domains. These links likely lead to phishing pages or further malware downloads, consistent with a malicious PDF dropper.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9922

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://ketchas.ru/uplcv?utm_term=paris+the+expedition+sled+960
    • http://studiotecnicobonoli.com/userfiles/files/fukomapifixofe.pdf
    • http://mobilephleb.com/clients/2/2d/2d2188d13063160162e6e2bbcdac547d/File/6195665698.pdf
    • http://netinflux.net/userfiles/file/66874379642.pdf
    • https://doellefjelde-mussemarked.dk/images/newsmail/file/fisafugixu.pdf
    • http://esistore.be/userfiles/file/venaximemaxofabuz.pdf
    • https://kham.vn/userfiles/file/vepuwapujenadepurikaroxaf.pdf
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/9604e472e7379289a75ed80216cbebbd/34314388057.pdf
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160994c3815ce5---busuvu.pdf
    • http://szyldkj.com/luodan/images/userfiles/file/31995657922.pdf
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/hiql0mf3g2lg91lcqmkq153hs9/muguduz.pdf
    • http://landpas.pl/upload/file/68591602331.pdf
    • http://strefa-fitness.pl//fckeditor/editor/filemanager/connectors/phpplikifile/baxen.pdf
    • http://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/4c13cb1fff5f15e430a4caefe7d2d09b/91320380032.pdf
    • https://leesman.com/wp-content/plugins/super-forms/uploads/php/files/e23334b214f03a4a948052fac4bbe961/nilupivadal.pdf
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160826b4a835c7---tuxofelalipedadut.pdf
    • http://cecev.com/stockages/files/wovew.pdf
    • http://quaker1960.com/clients/3/34/346d0055920ff30d27c63167e405b0e7/File/baguwugi.pdf
    • https://xn--80adj7cxa.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/0df63d3014820d168396de1b6c2da6d3/dimizoronokejasozatubu.pdf
    • http://xpressup.com/userfiles/file/lulerojuzorifurorumirud.pdf
    • http://phs1961.com/clients/2/29/29da8dc1278d8f1c58a3d16208bcb4e7/File/85813986446.pdf
    • http://cokhixnktientien.com/Images_upload/files/salazepo.pdf
    • https://revapackers.com/wp-content/plugins/super-forms/uploads/php/files/67m2n2qkkfjcvmlnibculmsa0t/xidamavoladijemazi.pdf
    • http://reclaimsplus.com/wp-content/plugins/super-forms/uploads/php/files/509038019963363811af98ea16daf7b4/kowazofasudilabijubefeno.pdf
    • https://donnasalon.ru/wp-content/plugins/super-forms/uploads/php/files/9d29f5e508ac7cad70b66df2fffb2fb4/56254647030.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d22a.bin
3804090569788f32cdd8921fd5718490419fd6f73734fa974463d6f23398efca
pdf-font-stream PDF embedded font (sfnt) at offset 0xD22A 17620 bytes
font_01_sfnt_off0000ff9a.bin
011fadaadb30219887150f152b5867f28ee67e937c340c716c7fc373de039042
pdf-font-stream PDF embedded font (sfnt) at offset 0xFF9A 16244 bytes
font_02_sfnt_off00011599.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11599 16792 bytes
font_03_sfnt_off00012db0.bin
60b5c7884f2d4c7fb71842d5901ed0cf43deec8c0b0c58fc3d9a2b11fc1fa949
pdf-font-stream PDF embedded font (sfnt) at offset 0x12DB0 11048 bytes