Malicious PDF — malware analysis report

Static analysis result for SHA-256 ae59b1a7d8a24914…

MALICIOUS

PDF

72.2 KB Created: 2021-09-29 07:55:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: a5f9498d8fe4b2bdbb99f39a40797772 SHA-1: b0ce5c2d75212455d8793becf7f92245d455dd14 SHA-256: ae59b1a7d8a249149746e35032ca8c98a6f9cd1152e28b09cbf639fae0a23fd9
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, and it contains embedded JavaScript. It also exhibits characteristics of a link farm, with numerous URLs pointing to potentially compromised or disposable hosting, suggesting an attempt to redirect users to phishing or malware sites. The presence of embedded JavaScript indicates an intent to execute code within the PDF viewer.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9908

Heuristics 7

  • 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.
  • 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://laborke.ru/uplcv?utm_term=exercises+for+upper+chest
    • http://thekreativecompany.com/uploaded_files/userfiles/files/pomoro.pdf
    • http://northmarking.com/userfiles/files/54189330132.pdf
    • http://inannamsao.com/uploads/files/bazavofowojevipa.pdf
    • https://benhgout.net/uploads/Files/file/daxokebe.pdf
    • https://www.huaikrachaohospital.go.th/assets/global/lib/ckfinder/userfiles/files/sesaginabu.pdf
    • https://papersacksfactory.ae/images/bulk_images/files/43284015861.pdf
    • http://cbstav.cz/file/pasibufes.pdf
    • http://www.detskaoptika.cz/ckfinder/userfiles/files/gomuruxopuzekugijaxunu.pdf
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16145e84bf1df9---59908149356.pdf
    • https://ildiko-szepsegszalon.hu/userfiles/file/tojupowizemamupetu.pdf
    • https://www.traitagri-solutions-alternatives.fr/ckfinder/userfiles/files/xakuvudumosuzesuvuremoruk.pdf
    • https://kamionosnyelvlecke.hu/userfiles/file/73406347521.pdf
    • http://xetaihyundai.net/upload/files/kinejos.pdf
    • http://teen.plovdivweek.com/js/ckfinder/userfiles/files/15716087733.pdf
    • http://www.medicellbank.com/userfiles/files/bozaguzedemisa.pdf
    • http://hindustanadvancedsolution.com/t/tutorfirm/uploads/ck/files/fanuxesomovojozaxilakix.pdf
    • https://cortemadera.com/wysiwygfiles/file/dunenabegelupidumazewumew.pdf
    • http://jplus-ag.com/upload/files/BodyFile__6144058C61288.pdf
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/fa9fe4f426fd42c7dde51b47b46eeca7/26114797361.pdf
    • http://daotaoyduoc.org/wp-content/plugins/super-forms/uploads/php/files/2c1a5e7377a918a8d70a6eb7e197acb4/gijabijojipisafixerabusej.pdf
    • http://kepco-group.com/uploaded_files/userfiles/files/53901233332.pdf
    • http://mxagproducts.com/upload/browse/file/6925066969.pdf
    • http://puginternational.com/ckfinder/userfiles/files/72722211604.pdf
    • http://csc-vietnam.vn/uploads/userfiles/file/dirubo.pdf
    • https://magerp.org/upload/files/49742748443.pdf
    • https://myhoorayhealth.com/wp-content/plugins/super-forms/uploads/php/files/4cece398ed3acf8c8ffebc35810bcafa/guvefabe.pdf
    • http://nirmalapublicschoolerumely.com/userfiles/file/75274985347.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_off0000b819.bin
2a1fc50949ee6110a04a052d66f7ea22dde89cea4bab6fa63d5e93833b443c84
pdf-font-stream PDF embedded font (sfnt) at offset 0xB819 10448 bytes
font_01_sfnt_off0000cffd.bin
b4ef0638dab8a28b4e8be85a6b8a51ff98f5fe4ccc646b2b28ec4576833adbc4
pdf-font-stream PDF embedded font (sfnt) at offset 0xCFFD 16816 bytes
font_02_sfnt_off0000fae5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFAE5 16792 bytes