Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc87a923c6acb702…

MALICIOUS

PDF

147.1 KB Created: 2021-07-10 05:29:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d5b8a6978987968d84c41a24d06200e6 SHA-1: 7fb1ac060790f05bac8040da163a993bbdb128ed SHA-256: bc87a923c6acb702e8a223d9a599089d637f13f97afbc8796ad35e95b06c2859
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample contains embedded JavaScript and numerous external URIs, many of which point to compromised WordPress sites acting as link farms. The ClamAV detection and ML classifier strongly indicate malicious intent, likely for phishing or malware delivery. The embedded JavaScript is a common technique to initiate malicious actions upon opening the PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9922

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://allytemp.ru/uplcv?utm_term=scientific+notation+test+answer+key
    • https://seroinstitute.com/wp-content/plugins/super-forms/uploads/php/files/423ca8abb92b7637e7de81a7d03d8042/87396056945.pdf
    • http://igigeothermal.jp/userfiles/file/24977536566.pdf
    • https://n95america.com/wp-content/plugins/super-forms/uploads/php/files/7df98be968faac3ec9be4cbc8491e218/jogomodutepomani.pdf
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/160845b1da56b3---90685389957.pdf
    • http://autoscuolavalerio.it/userfiles/files/diwareba.pdf
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/kbutrt6f066tm9rjr6m6assu23/rodum.pdf
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609611dc64f6c---fadewumumoxirel.pdf
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/21d6e251df8daa253c03cb928f905424/bomukog.pdf
    • https://www.dekleinewerf.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a7f9093ac5d---mujawad.pdf
    • http://www.yourhealthyourchoice.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608a287184540---rujidag.pdf
    • https://regenerativetherapyforpain.com/wp-content/plugins/super-forms/uploads/php/files/c462829a9b5b61752fdaee3c623ceefa/kuwajaki.pdf
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/00ho8f0ht05nbn09mcvilu3dk7/guzularizomevetad.pdf
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609c956b6cd8e---67888398633.pdf
    • http://nuyewpilot.academy/wp-content/plugins/super-forms/uploads/php/files/9edb837a71771537b7ae5d16e15ee260/vomatebaxixodamukisim.pdf
    • https://micast.de/wp-content/plugins/super-forms/uploads/php/files/1t5oucbgca6v4njild13ldtnu5/buvolevagijekovos.pdf
    • https://burragebrothers.com/demo/jolie/beta/userfiles/files/27297910621.pdf
    • http://xn----8sbfeahwarn6ac1adp3fb2p.xn--p1ai/userfiles/file/9494995136.pdf
    • http://www.rlktechniek.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160a6c001dc357---26807889851.pdf
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607797779ed76---59440896850.pdf
    • http://franzoesischebulldoggen.eu/userfiles/file/wujenowo.pdf
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/64856f05a841ea8e4780873f686f97cf/44687753019.pdf
    • http://santiagoporter.com/js/ckfinder/core/connector/php/files/rumonif.pdf
    • http://skuplaptop.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1607568d568f6c---26253061976.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_off0001dd90.bin
1ca5a58e79d5ddb80b4850cc1effe945f5dc26e3b3ac5d6061514226fc9cf720
pdf-font-stream PDF embedded font (sfnt) at offset 0x1DD90 10652 bytes
font_01_sfnt_off0001f632.bin
1e9344c02886fd1168877dd6951694282cf6726ce22a50d691ff25ae2f035701
pdf-font-stream PDF embedded font (sfnt) at offset 0x1F632 18392 bytes
font_02_sfnt_off000226d0.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x226D0 16792 bytes