Malicious PDF — malware analysis report

Static analysis result for SHA-256 11b268c80a8d65b4…

MALICIOUS

PDF

80.7 KB Created: 2021-09-23 16:53:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 4ee3989cb2addea9277023668d3a60a6 SHA-1: 7ff8726bbea70bf7206f60465917b36238c5cffa SHA-256: 11b268c80a8d65b44a61c9e012b9600b3adbaf82bc1d2da466af679770098b16
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV detecting it as Pdf.Phishing.Trojan. The numerous embedded URLs point to a link farm hosted on various domains, many of which appear to be compromised or disposable, suggesting an attempt to redirect users to malicious content. The document body is heavily obfuscated and unreadable, but the presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics indicates the primary function is to host and link to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9933

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://synerhu.ru/uplcv?utm_term=how+to+print+editable+pdf
    • http://www.patriarca-batiment.com/ressource/site-image/files/58120267016.pdf
    • https://www.spoton.pet/wp-content/plugins/super-forms/uploads/php/files/292sfkufpmrc6jabkiopdlaq7u/pupubufozipe.pdf
    • http://racecross.com/upload/edito_fckeditor/file/xixeziserakatasozixufutu.pdf
    • http://hotelpenza58.ru/ckfinder/userfiles/files/35788758453.pdf
    • http://www.icodar.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d09140b089---65384233547.pdf
    • http://jshtextile.com/UserFiles/file///45293803014.pdf
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/161331b6879b4e---fujakefi.pdf
    • http://ytovietnam.net/ckfinder/userfiles/files/30050075887.pdf
    • https://karpzbeldowa.pl/uploads/userfiles/files/tojavikep.pdf
    • https://studiogreenwich.ru/wp-content/plugins/super-forms/uploads/php/files/3db1e978eaca98b81c6ce2cc7759c173/64648733912.pdf
    • https://laserbeautymachine.net/d/files/31021473260.pdf
    • https://akproauto.com/nbloom/fckuploads/file/jixutodokurat.pdf
    • http://terralis.net/catalogue_dynamique/file/rasudegatinulapibediwuv.pdf
    • http://cec-intl.ru/app/webroot/files/file/mejizuka.pdf
    • http://www.liveartsaskatchewan.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b7fef4a05d---somedalutetixepajutekelo.pdf
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614b71ef656b6---91471802643.pdf
    • https://turasmobilya.com/img/editor/image/file/pazuk.pdf
    • https://congchungnguyenlieu.vnpec.xyz/uploads/files/zajolasade.pdf
    • http://palakkadtourism.in/ckfinder/userfiles/files/24264628467.pdf
    • http://yanarfabrics.com/firma/files/zebesunakakolejipesezaj.pdf
    • http://szkolaprywatnaleszno.pl/userfiles/file/sujaniviwuxavetupotimir.pdf
    • http://enovosti.info/ckfinder/userfiles/files/dibodupag.pdf
    • http://araratmebel.ru/img/file/lisubutadusinob.pdf
    • http://ganteltechnology.com/system/userfiles/file/22508850643.pdf
    • http://stroyvodservice.ru/upload/File/31763107863.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_off0000c087.bin
cfc3490076be71abfbd132c9210abf5652b420e4e5ec912b132a02d83898da26
pdf-font-stream PDF embedded font (sfnt) at offset 0xC087 17300 bytes
font_01_sfnt_off0000ed97.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xED97 16792 bytes
font_02_sfnt_off000105a8.bin
06f1d5f5a9083a80364da0885936c8ddb2848b41a67694407b5e75bff462a068
pdf-font-stream PDF embedded font (sfnt) at offset 0x105A8 16616 bytes
font_03_sfnt_off00011cf0.bin
90936e2aac57cc1709376b2e29e932288d78eec4634547ed83fa137ab436525c
pdf-font-stream PDF embedded font (sfnt) at offset 0x11CF0 10540 bytes