Malicious PDF — malware analysis report

Static analysis result for SHA-256 53f375aa8561befa…

MALICIOUS

PDF

85.1 KB Created: 2021-09-19 10:23:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b8ecfada0ffbc4555ff728b6d919cd43 SHA-1: fcabaf711f97ad5803cef4c3f0f6f59bb15a8a49 SHA-256: 53f375aa8561befade069007412f5c6b8c486fd665907c4ac0c2b426fd1e2d29
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicating a link farm designed to redirect users. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or distributing further malware. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious document delivery.

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://infrive.ru/uplcv?utm_term=unturned+bomb+id
    • https://ketex.com/trcgp/ckfinder/userfiles/files/lojute.pdf
    • https://nffcd.org/userfiles/files/xadabatugup.pdf
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/ejdov3d9e8vqn92n3b205v7q3s/tomawifi.pdf
    • http://pomocnaukowa.net/Upload/file/23310391635.pdf
    • https://harmony.im/userfiles/file/18984791431.pdf
    • http://csc-0411.com/userfiles/file/20210911175709_fod8v0.pdf
    • http://www.southforconstruction.com/frontend/web/ckfinder/userfiles/files/48466692451.pdf
    • https://dafelia.com/files/pumawub.pdf
    • http://www.taylormadetc.com/siteadmin/ckfinder/userfiles/files/xovitevasinubizosojikebip.pdf
    • http://dobryremont.pl/ebobas/portal/app/webroot/img/tmp/file/16306571463575.pdf
    • http://mutamobilya.com/images_upload/files/viregopaxepogajodopoxe.pdf
    • http://apex-architect.ru/images/file/66868755247.pdf
    • https://xo-sound.ru/userfiles/file/fiferevaxalesoduzeze.pdf
    • http://idealhca.com/admin/images/file/liwutikogekideweko.pdf
    • http://www.nanodrywash.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b17b9348d5---88617992845.pdf
    • https://daaeportrett.no/upload/file/wetutokirivajex.pdf
    • https://artistprasanna.com/userfiles/file/31247210274.pdf
    • http://xn--2osv9pt2jfpt.com/uploadfiles/files/pusavixasunafasezuga.pdf
    • http://carneslaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/botapufoxirinulutar.pdf
    • https://www.penyembuhanholistikreiki.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612e9e2134bef---gukoxabekenadewe.pdf
    • https://rosedreamholidayhomes.com/ckfinder/userfiles/files/53894408132.pdf
    • https://oncallanatomist.com/ckfinder/userfiles/files/98187154525.pdf
    • https://roarmysecurity.ro/mm/file/nutabulevotutowu.pdf
    • https://mrpressconsulting.com/UserFiles/file/56944470957.pdf
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161426ad911de3---65952008440.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_off0000bfdc.bin
4e1e5d1499031bbc4c266851bff8254f18715aecf7a5a879360c2f17977461f4
pdf-font-stream PDF embedded font (sfnt) at offset 0xBFDC 24824 bytes
font_01_sfnt_off00010041.bin
71fcb50aa39953dad23b1aac2a80d5ebe6c80a2c6a8169abba0b68d6d9135f73
pdf-font-stream PDF embedded font (sfnt) at offset 0x10041 10280 bytes
font_02_sfnt_off00011752.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11752 16792 bytes
font_03_sfnt_off00012f63.bin
0de48d09b0091e2dcca1524f119562a2650f4f0070c1ddb91a42211a810a88bd
pdf-font-stream PDF embedded font (sfnt) at offset 0x12F63 16160 bytes