Malicious PDF — malware analysis report

Static analysis result for SHA-256 a576f19bf36a1734…

MALICIOUS

PDF

83.4 KB Created: 2021-07-09 07:30:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 81fa76c8d182896dd3b0564aa817df78 SHA-1: 242cda0fc442f17b5536204bbd677f37e4949c66 SHA-256: a576f19bf36a173462180a00389cffa8ef4bb9f68b27975acff92bb7d211c375
156 Risk Score

Malware Insights

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

The sample is identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to compromised CMS upload storage and disposable hosting, suggesting it's part of a link farm designed to redirect users to malicious sites. The PDF structure and embedded URLs point towards an attempt to exploit vulnerabilities or trick users into downloading further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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://vuaship.com/wp-content/plugins/super-forms/uploads/php/files/5gmf6fs0aolhun5h6uqf0t3n19/zenigixuto.pdf
    • http://fonnepal.org/userfiles/file/67304888043.pdf
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a64148b4b4f---9712804463.pdf
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/7as5v0q06dmli431meo45ind1o/485587237.pdf
    • http://clarksville.net/wysiwygfiles/file/lunanatezibovefosomonibet.pdf
    • http://jnnycc.org/userfiles/file/faxatimebozevuraworiwir.pdf
    • http://architects-desk.com/uploadsfile/63276397011.pdf
    • http://agarimo.com/archivos/archivos/63861919799.pdf
    • https://apoc.com.au/wp-content/plugins/super-forms/uploads/php/files/136b72d20c500410f1e46785c4e32135/43150281569.pdf
    • https://wavesmaroochydore.com/wp-content/plugins/super-forms/uploads/php/files/tl7tg34p06i40s6bmicn8upsqu/34465948434.pdf
    • https://yucekalipmakina.com/tsrm1/img/userfiles/file/tekozoxisa.pdf
    • http://vdadanang.vn/app/webroot/assets/files/47308754303.pdf
    • https://www.visitrwanda.com/wp-content/plugins/super-forms/uploads/php/files/9ac6f9f582ec075105a7ae9c8504c2d9/bebipilaxipomuvurovaxise.pdf
    • http://villaturri.it/wp-content/plugins/formcraft/file-upload/server/content/files/16097ceef4bdb5---48255164639.pdf
    • http://matrixuniverzum.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160cec2811601e---vijuxuwi.pdf
    • https://its-bulgaria.bg/files/file/pizixopi.pdf
    • https://husvagnsexpo.se/wp-content/plugins/formcraft/file-upload/server/content/files/16078664bb8c1e---10080099872.pdf
    • https://rclurie.com/wp-content/plugins/super-forms/uploads/php/files/739e787273a560051893938351b1c84e/pufadafafovuxeteki.pdf
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/uectk1h8qo8fqmm8ee43qkr7d0/tedelaruxuvesufedik.pdf
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ad3ec31011d---puwunifuwarelusurixupuveg.pdf
    • http://meble-tk.pl/userfiles/file/26623392262.pdf
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/160a86e273bc74---92557120417.pdf
    • http://shinserviceodi.ru/wp-content/plugins/super-forms/uploads/php/files/6818e2476833585f24cf1ca5b490b9e9/30956366595.pdf
    • http://sb-78.ru/files/file/4187398854.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=harvard+business+review+effective+communication+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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e409.bin
5e79f2c12d6bc5465046318df2761065eccbe1c6de4fbbc92eb1a16dca89d02d
pdf-font-stream PDF embedded font (sfnt) at offset 0xE409 11120 bytes
font_01_sfnt_off0000fdcb.bin
6be33b69957b6d331736ae1e7508bd133cf632f54d8c0b7eb2f491a42b62d23e
pdf-font-stream PDF embedded font (sfnt) at offset 0xFDCB 16428 bytes
font_02_sfnt_off00012809.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12809 16792 bytes