Malicious PDF — malware analysis report

Static analysis result for SHA-256 550766aee10f11e0…

MALICIOUS

PDF

80.3 KB Created: 2021-09-01 01:58:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: b45b2c2b50f82c5f57ea0f87e4f08d70 SHA-1: 6507dec5a1f597ad987847e963648eebe4424e1c SHA-256: 550766aee10f11e019ef28f1eb0e830e402eed5d57ca8a887a321b0937621ec9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a link farm, with multiple URLs pointing to compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The presence of numerous external URIs and compromised host links suggests an attempt to redirect the user to a malicious site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/d6afba2f8552e80f28ae8908cfb2ec0b/7059651268.pdf In PDF document text
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/160adf62607608---51103648448.pdfIn PDF document text
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/87ff966beaf62e58cc9d473c0aac38c8/kuzugepelumemodojemov.pdfIn PDF document text
    • https://cardion.dk/gfx/fckimages/file/77281305788.pdfIn PDF document text
    • http://minhnguyenvn.com/uploads/userfiles/file/vukolexamenibilil.pdfIn PDF document text
    • https://www.psk.com.au/application/third_party/ckfinder/userfiles/files/gefekizazobafop.pdfIn PDF document text
    • http://webinaris.org/ckfinder/userfiles/publics/files/6523313844.pdfIn PDF document text
    • https://my-natural-style.net/upload/files/78894890710.pdfIn PDF document text
    • https://nguyenhungstone.com/uploads/image/files/14773784113.pdfIn PDF document text
    • https://earthchartercities.org/wp-content/plugins/formcraft/file-upload/server/content/files/1608473075f994---zomolaminakeduvanisi.pdfIn PDF document text
    • https://www.koreayokogawa.com/ckfinder/userfiles/files/64402512783.pdfIn PDF document text
    • http://yongqingtech.com/d/files/85501499100.pdfIn PDF document text
    • http://phatnang.com/media/ftp/file/59482581320.pdfIn PDF document text
    • http://davidhammerstein.org/userfiles/file/vavorovojevumelaferizuruj.pdfIn PDF document text
    • https://agrando.cz/files/file/kawusenajerawitovojo.pdfIn PDF document text
    • https://hospvetcentral.pt/site/upload/file/dikerazo.pdfIn PDF document text
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608165233c32a---katani.pdfIn PDF document text
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/160c5e1cde22c1---59967446806.pdfIn PDF document text
    • http://joelcsimonesq.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/jorawix.pdfIn PDF document text
    • https://defaico.com/d/files/98182579477.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=financial+accounting+2+textbook+pdfPDF 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_off0000d8c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8C4 16108 bytes
SHA-256: 34d9ff2ccd259d78ab4890ded939c6f7f84d962aa0aa6178b07947f637708088
font_01_sfnt_off0001024d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1024D 11060 bytes
SHA-256: 4c84b82a6d74b952c849168255ef3636e24381c8bd70b9b796a81b26cea6240f
font_02_sfnt_off00011bd2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BD2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1