Malicious PDF — malware analysis report

Static analysis result for SHA-256 bce903106dff0691…

MALICIOUS

PDF

106.6 KB Created: 2021-08-16 07:42:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 47ccc401d3d5eeda8b88f2a6d452d147 SHA-1: 3a233ef4ff4cbd1a866ab429855035314d7018c0 SHA-256: bce903106dff06911a47c5ad11c95c2131e6909f56ff41ecb4625a312be65973
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous embedded URLs pointing to compromised CMS uploads and disposable hosting, suggesting a link farm designed to redirect users. The PDF structure and numerous external links indicate it's likely a phishing lure or a distribution point for further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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 https://synerhu.ru/uplcv?utm_term=ejemplos+de+bacterias+gram+negativas PDF link annotation
    • http://strandedtattoo.net/file/zotilunulonaxurenedoduji.pdfIn PDF document text
    • http://anhuicrew.com/upload_fck/file/2021-4-29/20210429150410711153.pdfIn PDF document text
    • http://www.circoloaletrium.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607af54c3b1f7---16664300132.pdfIn PDF document text
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/de2302d453a739f80b09e703cd2be3cd/29438748485.pdfIn PDF document text
    • https://ctapigroup3.com/contents//files/48830777264.pdfIn PDF document text
    • http://cocoal.com/uploads/file/vevuwilijej.pdfIn PDF document text
    • http://bellezaeimagen.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160fdbdc47d567---73872756978.pdfIn PDF document text
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609d94662b146---17243209832.pdfIn PDF document text
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081c40ce73e2---57280578917.pdfIn PDF document text
    • http://basyapiemlak.com/yukleme_klasoru/userfiles/file/72944664169.pdfIn PDF document text
    • https://www.landalastadservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160768cd3a5d83---90733723229.pdfIn PDF document text
    • http://kowel.com/ckfinder/userfiles/files/1622282745.pdfIn PDF document text
    • http://closehorses.com/userfiles/file/sokidanefewu.pdfIn PDF document text
    • https://immo-cjeanpaul.lu/userfiles/files/zolalasakew.pdfIn PDF document text
    • http://hk-sai.com/ckfinder/userfiles/files/mukofize.pdfIn PDF document text
    • http://taxicityplus.ru/userfiles/file/gamosuwerutulale.pdfIn PDF document text
    • http://blog.crowdly.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609bc8e77c8a0---11185120578.pdfIn PDF document text
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d26c68ca46---jetimoreturupofurikipazor.pdfIn PDF document text
    • https://siphouse96.com/wp-content/plugins/super-forms/uploads/php/files/9168a8c5b79239b62fcbd7d6dd8a0f88/maxobopisolewitomo.pdfIn PDF document text
    • https://voolabs.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ced8dd30c39---40610143037.pdfIn PDF document text
    • https://matfreklam.com/calisma2/files/uploads/mefetafufovadidevow.pdfIn PDF document text
    • https://m-co.de/wp-content/plugins/super-forms/uploads/php/files/87ibhqsdoft1lqpvr1hrr6iv2i/73044789041.pdfIn PDF document text
    • http://clinivetmadonnadirosa.eu/userfiles/files/xubifuxobe.pdfIn PDF document text
    • http://hncastlecable.com/d/files/visod.pdfIn PDF document text
    • 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_off00013ac2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13AC2 11176 bytes
SHA-256: 1d61e4b0e35044d51efed8fefc38c67946cbf2dd47fed2999d66552ebe6034b6
font_01_sfnt_off00015467.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15467 18184 bytes
SHA-256: e9a00e824b0cd81b9ce3ace39c2f65d0fb4116b828acfbc593eb13438072f312
font_02_sfnt_off00018299.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x18299 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1