Malicious PDF — malware analysis report

Static analysis result for SHA-256 90a30b48d283526a…

MALICIOUS

PDF

84.7 KB Created: 2021-09-14 01:19:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 8d5cbe3a2ce8da1dc523176586599b90 SHA-1: b66c6ba216e3e651520cdc880bb9b124dff67b63 SHA-256: 90a30b48d283526acc20d1c49755965696ca4926581d265fccffde67f438be9b
156 Risk Score

Malware Insights

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

The sample is a PDF file flagged by ClamAV and an ML classifier as malicious. It contains numerous links, many pointing to compromised websites or disposable hosting, suggesting a link farm designed to redirect users. The presence of external URI heuristics and the compromised CMS upload link firing indicate that the PDF is likely used to distribute further malicious content or lead users to phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://hkxhjfc.ltd/uploads/files/20210910100115.pdf In PDF document text
    • https://pass-eco-energies.com/ckfinder/userfiles/files/jokelabolul.pdfIn PDF document text
    • http://shangrilayunnan.com/ckfinder/userfiles/files/99016239898.pdfIn PDF document text
    • http://5thaveseniors.org/userfiles/file/42437693237.pdfIn PDF document text
    • https://akproauto.com/nbloom/fckuploads/file/2092333148.pdfIn PDF document text
    • https://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/ea5dc896868fa8590d07f04ac25ffa8e/jurivuto.pdfIn PDF document text
    • http://la-roofers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613d1b0826eee---bivagu.pdfIn PDF document text
    • http://mellorymotors.ru/admin/ckfinder/userfiles/files/37166710131.pdfIn PDF document text
    • http://bradzo-ep.com/uploads/files/53995017852.pdfIn PDF document text
    • https://vitanov.rs/files/36252463317.pdfIn PDF document text
    • http://thy-environment.com/userfiles/files/wuloja.pdfIn PDF document text
    • http://nazycakes.com/userfiles/file/99171852747.pdfIn PDF document text
    • https://swotin.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613364b77efc8---95572999694.pdfIn PDF document text
    • http://webinaris.eu/ckfinder/userfiles/publics/files/99018981412.pdfIn PDF document text
    • http://philipsphotographystudio.com/75033944600.pdfIn PDF document text
    • https://mantyobras.com/userfiles/file/12856443154.pdfIn PDF document text
    • http://gabinetpro.gabinetpro.pl/kosmetyczka/krakow/files/tavipitexobewafife.pdfIn PDF document text
    • https://funcarele.com/ckfinder/userfiles/files/6604509878.pdfIn PDF document text
    • http://benthanhsgfarm.net/images/uploads/files/15973853221.pdfIn PDF document text
    • https://omprintandpack.com/userfiles/file/katazosulo.pdfIn PDF document text
    • http://hoya889.com/upfile/files/20210905091411.pdfIn PDF document text
    • https://borderpak.com/wp-content/plugins/super-forms/uploads/php/files/21404cf82dff93d3480d41792b43ac63/2578212644.pdfIn PDF document text
    • http://www.corazondelsol.es/ckfinder/userfiles/files/28000229514.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=fantastic+beasts+and+where+to+find+them+2+123moviesPDF 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_off0000e1b4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1B4 18892 bytes
SHA-256: e377be4f90b44177715e39e7581f87cf5777148a1075afc7b4a901e87ab4155e
font_01_sfnt_off000112a4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112A4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012abb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12ABB 11308 bytes
SHA-256: d245ac711f9a7de81b8237207a76987a64933f9ae7346393617f36ddaf01f193