Malicious PDF — malware analysis report

Static analysis result for SHA-256 3f8ce1dc240b3d50…

MALICIOUS

PDF

87.1 KB Created: 2021-07-25 09:42:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: ec20b07307beb49f2e14152c8343a56e SHA-1: bdeaafd0627f0615020e53e088b8de2eca38d423 SHA-256: 3f8ce1dc240b3d5005b44592a1418d978f124490e4d1cd1ad13718ae958218df
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection for 'Pdf.Phishing.Trojan'. The document contains a link farm pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to malicious or phishing content. The presence of external URIs and a high ML classifier score further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://nfrostov.ru/upload/files/relajukisujitamumigo.pdf In PDF document text
    • https://www.nvsrolko.org/ckfinder/userfiles/files/fojomatimunubupimato.pdfIn PDF document text
    • http://adamlegal.com/userfiles/file/88647864451.pdfIn PDF document text
    • https://ocbond.org/userfiles/files/42652861663.pdfIn PDF document text
    • https://mamproducciones.es/wp-content/plugins/formcraft/file-upload/server/content/files/160c69e85058be---reviwirugokog.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16092e4e976e2a---tolala.pdfIn PDF document text
    • https://centrobrands.com/wp-content/plugins/super-forms/uploads/php/files/281996721ba079562c642587381fbd8c/96516160322.pdfIn PDF document text
    • http://hakkabrothers.com/userfiles/file///sakatiluguwafuke.pdfIn PDF document text
    • http://maremio.ru/admin/ckfinder/userfiles/files/solukebutukinefa.pdfIn PDF document text
    • https://thejasmineway.net/wp-content/plugins/super-forms/uploads/php/files/dha7l6vc91ies2duv7b0hv6lph/52752108765.pdfIn PDF document text
    • http://kardelendalgicpompa.com/uploadfiles/file/badonejuxex.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/5330158c7bf830839632bdf1f2ba8375/37540417078.pdfIn PDF document text
    • http://anthonyvienna.com/sites/default/files/file/41396624140.pdfIn PDF document text
    • https://too.kg/wp-content/plugins/super-forms/uploads/php/files/ad6874f28ef3c131718bf0e7311299db/97499062404.pdfIn PDF document text
    • http://liily.jp/upload/file/20210722114915.pdfIn PDF document text
    • https://kamber.dk/wp-content/plugins/super-forms/uploads/php/files/e4a0ba3bf3285f27159a02ba47790229/44058423974.pdfIn PDF document text
    • http://jnafarms.com/clients/864068/File/funugilunin.pdfIn PDF document text
    • https://gastrotest.co/ckfinder/userfiles/files/posumasejutufup.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160af98cb93cb7---bunodegefabesex.pdfIn PDF document text
    • https://mollis.rs//files/sudujobumirawesa.pdfIn PDF document text
    • http://gift-founder.com/archive/upload/files/58043211265.pdfIn PDF document text
    • http://medica-eg.com/userfiles/file/bodivegisuderi.pdfIn PDF document text
    • https://chiuman-hk.com/images/file/34609805384.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=como+imprimir+comprobante+de+pago+pension+issstePDF 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_off0000ef90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF90 17868 bytes
SHA-256: 4b7ae456a5c00c21619a97505e841af55381c4837bb4f5256db59856014c544e
font_01_sfnt_off00011d2d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D2D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013544.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13544 10980 bytes
SHA-256: 57064d7d147cdd9e5284a80b857aa501ca524830804ee55374a757fad5357781