Malicious PDF — malware analysis report

Static analysis result for SHA-256 39175762ab25a1d9…

MALICIOUS

PDF

70.3 KB Created: 2021-09-28 04:56:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 8d054aa5c5ca3bf5379cfe4f07bb2926 SHA-1: 24f2fddf982c7aea0c2f70937f10d6d06bc46303 SHA-256: 39175762ab25a1d909e6c3c0c8bef29141759d7ea51b710ca1ebd492574bb125
104 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF document containing embedded JavaScript, which is a common technique for executing malicious code. It also features a link farm pointing to compromised WordPress upload storage and other disposable hosting, suggesting an attempt to distribute further malicious content or phish users. The ML classifier strongly flagged this PDF as malicious, supporting the assessment of its attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • 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 http://www.sainteuphrasia.com/www/js/ckfinder/userfiles/files/kejubul.pdf In PDF document text
    • http://mirutte.com/newsfiles/files/39954033400.pdfIn PDF document text
    • http://ultrabeauty-ff.ru/userfiles/file/ruxituju.pdfIn PDF document text
    • http://tgroupsrl.com/userfiles/files/21627031454.pdfIn PDF document text
    • http://phfamilyrestaurant.com/uploads/files/60050000795.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/161505135c59f7---87063763228.pdfIn PDF document text
    • https://toptenstudy.com/upload/files/BodyFile__613C2B5474695.pdfIn PDF document text
    • http://reklama-v-sochi.com/ckfinder/userfiles/files/49148816252.pdfIn PDF document text
    • http://realestatemiami.com/userfiles/files/ritavesufe.pdfIn PDF document text
    • http://sk-massimo.com/js/upload/files/7220239900.pdfIn PDF document text
    • http://piazzademarini3ge.com/userfiles/files/56508255601.pdfIn PDF document text
    • https://copyjokertw.aw6.tw/uploadfile/qu4_qu106_com/files/likijopenumidojivoji.pdfIn PDF document text
    • http://mingmitrcoffee.com/user_img/files/6038821940.pdfIn PDF document text
    • https://cbolean.com/wp-content/plugins/super-forms/uploads/php/files/0f902b40869da98b3360ee49be77352c/tazugi.pdfIn PDF document text
    • http://synergytaekwondo.com/click2buy_newp/userfiles/file/30695144101.pdfIn PDF document text
    • http://descanso.verareyes.com/ckfinder/userfiles/files/75055658012.pdfIn PDF document text
    • http://sanchariglobal.com/userfiles/file/70892414959.pdfIn PDF document text
    • http://sts-logistika.ru/wp-content/plugins/super-forms/uploads/php/files/a3f4d9f47e402f3d3f5a752115fc83a8/sesudawu.pdfIn PDF document text
    • http://standdominica.org/files/files/jedupizogiku.pdfIn PDF document text
    • http://cosmoscm.com/contents/files/rewodileberifibojiwuwebov.pdfIn PDF document text
    • https://www.oalysa.cz/ckfinder/userfiles/files/joviwujabipobotinakalunum.pdfIn PDF document text
    • http://kibbkw.com/uploads/files/fugofuj.pdfIn PDF document text
    • https://ateneoarbonaida.com/wp-content/plugins/formcraft/file-upload/server/content/files/16151799273bcd---gerinuwaruladadeze.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=golf+games+to+play+with+3+playersPDF 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_off0000b2f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2F8 15016 bytes
SHA-256: 3fc1b5daee873f451486c5457f1b495a89fe28e5e1f79c794ca8b6778672fac4
font_01_sfnt_off0000d940.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD940 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f157.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF157 11112 bytes
SHA-256: 9e679091dc42e4b8fbfaa38135c547e61f53abe25d228065e3fc64a2c29085e1