Malicious PDF — malware analysis report

Static analysis result for SHA-256 856741e5d7d2382a…

MALICIOUS

PDF

95.0 KB Created: 2021-09-01 09:49:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-01
MD5: 183a1a3afacb82cafee5b2fcfd6d9b73 SHA-1: f5607ffb94483bb7841194612e8c9b57278d933e SHA-256: 856741e5d7d2382a2ff326472f15254a2304646fc27f66b6e110af7864a8eb1c
164 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories and presents a deceptive download button. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9928

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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 http://mp-journal.com/media/file/wupavixiwagavew.pdf In PDF document text
    • https://vijyaiprismcrm.com/userfiles/files/zevajawufim.pdfIn PDF document text
    • https://heykidsletscook.info/wp-content/plugins/super-forms/uploads/php/files/505b21f9db68d12187e6b2021c30bb6e/pixenomeju.pdfIn PDF document text
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/4d6cff3e414047b6c199ce3b93991110/73947022121.pdfIn PDF document text
    • http://hengtongrongshang.com/jingkelun/userfiles/files/20210708145819.pdfIn PDF document text
    • http://imi.vc/upload/files/69133443945.pdfIn PDF document text
    • http://yakutiaprime.ru/SITE/files/editor/file/79307577634.pdfIn PDF document text
    • https://law.com.sg/wp-content/plugins/super-forms/uploads/php/files/30be32c82bad1db67b405f89cc5d5afd/17015230303.pdfIn PDF document text
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6a0d42026d---pibilakabader.pdfIn PDF document text
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609cc25f55a89---lawanegivivevusoxovek.pdfIn PDF document text
    • http://kuehllawpc.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/gudaguvu.pdfIn PDF document text
    • http://vudafrique.com/wp-content/plugins/super-forms/uploads/php/files/cc78fb66bb4f5fedc63bfa236d1f39ba/33932841936.pdfIn PDF document text
    • https://www.chortho.co.uk/wp-content/plugins/super-forms/uploads/php/files/tha9touu7hinmpfmaamhleiifd/voferanivebukofupef.pdfIn PDF document text
    • http://pvsystexperts.com/wp-content/plugins/super-forms/uploads/php/files/mhku5trpckvcuof28smfhacam1/pubevubejinerazubenitita.pdfIn PDF document text
    • http://elenasteele.com/wp-content/plugins/formcraft/file-upload/server/content/files/160887b7b543ca---mixav.pdfIn PDF document text
    • https://sasalidayanisma.org/uploads/file/lasitezebumaba.pdfIn PDF document text
    • http://www.domplit2006.ru/ckfinder/userfiles/files/87661652474.pdfIn PDF document text
    • https://akconta.com/uploads/files/87060435691.pdfIn PDF document text
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/160756fc4114ae---foguvimeni.pdfIn PDF document text
    • http://www.hj-bouwt.be/wp-content/plugins/formcraft/file-upload/server/content/files/160fe1688629cd---64545987525.pdfIn PDF document text
    • http://www.tomasjelinek.com/img/pub/file/9425282412.pdfIn PDF document text
    • http://www.k-24.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a286a3785ae---70604741814.pdfIn PDF document text
    • https://robotics-institute.com/wp-content/plugins/super-forms/uploads/php/files/jenrn4fhhk1bbpj66k68hi42u9/19269453304.pdfIn PDF document text
    • https://rpdev.org/ckfinder/userfiles/files/dejusisilazewomawagut.pdfIn PDF document text
    • http://surausa.com/uploads/files/zugales.pdfIn PDF document text
    • http://inlikeflintlogistics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609869408f53c---modedogadamiliduli.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=simple+spanish+questionsPDF link annotation
    • 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_off00010ad8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AD8 10740 bytes
SHA-256: 3cc3a1b7738990b9551b7a788f985aa4c1682a552c66153f6ce05804424a5abb
font_01_sfnt_off00012344.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12344 19588 bytes
SHA-256: 9bd10c277b1e169ced99f4218863dcbc52be8135bcfc113ee90214605a4b5733
font_02_sfnt_off0001557a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1557A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1