Malicious PDF — malware analysis report

Static analysis result for SHA-256 bb07ffaa818a25c8…

MALICIOUS

PDF

85.8 KB Created: 2021-07-02 01:07:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 98ca31159764e9167ad8aabb8f8372db SHA-1: f64ad9b30e3d7410ad639cad1b31dac7e1fdf27a SHA-256: bb07ffaa818a25c8710e67819834d7e2d5216b0c8fb00d52d9a8030787e88f1b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm. Several URLs extracted from the document point to compromised WordPress sites and disposable hosting, suggesting an attempt to lure users to external resources. Embedded JavaScript streams are also present, which could be used to further obfuscate the malicious intent or execute additional payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://krisoc.ru/uplcv?utm_term=7+month+old+not+crawling+yet
    • http://yomamasushitogo.com/uploads/files/34172479296.pdf
    • http://primaneighbors.com/userimages/62357443695.pdf
    • http://tsg-vaganovskoe.ru/ckfinder/userfiles/files/38774372614.pdf
    • https://seerupit.dk/assens/file/denereduxefunexamewenumoz.pdf
    • https://completecollegestrategies.com/wp-content/plugins/super-forms/uploads/php/files/96bc6e6f603441ed4f5b8e40cc4afe85/65294658221.pdf
    • https://deltagroup.bg/uploads/file/96179624749.pdf
    • http://www.cenlajobinator.com/siteuploads/editorimg/file/10741228949.pdf
    • http://comicpapyrus.com/wp-content/plugins/super-forms/uploads/php/files/fe2e4ee48e1e0e411862c9d517d4f64d/pufokilaromefikukise.pdf
    • https://www.lavishlook.se/wp-content/plugins/super-forms/uploads/php/files/a96cd617f0038f320e16e40dfddcd2d9/tudexujetorobejosituwager.pdf
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/521795db27b45c9939a4b4ac2a8f81d0/zisatutodiwuxa.pdf
    • https://www.kngroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072e4ca55fbd---sajotuwuroganaputujebor.pdf
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/9b35f35c166cf4bbd817eadc3a644ab5/29325302822.pdf
    • https://www.web2business.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160d0092549fed---2952006831.pdf
    • https://polskieplytki.com/wp-content/plugins/super-forms/uploads/php/files/f0dda8a48b75f4223114389bad834ec8/somakudaf.pdf
    • http://ventiliatoriai.lt/js/ckfinder/userfiles/files/40657824701.pdf
    • https://simovi.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160ab2c8fe3e0f---jugademipiwewufuwejo.pdf
    • https://lea-inc.com/wp-content/plugins/super-forms/uploads/php/files/82a9a0723286d11f2508f019a71058c4/nilekedarafunikoporori.pdf
    • https://singaporeroadshow.com/wp-content/plugins/super-forms/uploads/php/files/527bddb5e2a9cbecba51f59fa0f178e2/26570352418.pdf
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a7729500220---65934011617.pdf
    • https://agrilaui.com/userfiles/file/wivemosavetijoj.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a05d8d2cad3---wilerurenegudewabelixexuk.pdf
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/160a578223d2f2---surunibegupapedepe.pdf
    • http://wsp.pl/userfiles/file/sapop.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_off0000ec8d.bin
c2f45832d8dbbf21cb2f3ec2cc8545ef505479b5cb8635a5948ebe062adb0e44
pdf-font-stream PDF embedded font (sfnt) at offset 0xEC8D 10804 bytes
font_01_sfnt_off00010511.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10511 16792 bytes
font_02_sfnt_off00011d23.bin
7ffa2735f596c8b2cab0f8a835d174e2afa00e6a83d890641cc8c2a81de7729e
pdf-font-stream PDF embedded font (sfnt) at offset 0x11D23 17172 bytes