Malicious PDF — malware analysis report

Static analysis result for SHA-256 7a858350b8c7895e…

MALICIOUS

PDF

73.6 KB Created: 2021-09-16 13:09:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 60c0377d7949319e22c3bba23e3a298a SHA-1: f85010c77ac1908792e71e29720707e5fe61e047 SHA-256: 7a858350b8c7895e27410979bd3bdf49babeb8f9a51f54577d91b6b48083744e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many hosted on disposable domains or compromised CMS uploads, indicating a link farm designed to redirect users. ClamAV detected this as Pdf.Phishing.Trojan, and the ML classifier also flagged it as malicious. The presence of embedded URLs and the link farm structure strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9963

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://chcial.ru/uplcv?utm_term=pcos+rujuta+diwekar+pdf PDF link annotation
    • https://nbretail.com.vn/ckfinder/userfiles/files/dokikajiwufokuverav.pdfIn PDF document text
    • https://ozora.schaffsen.com/contents/file/fidiferuwikutolemo.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f432385023---dadidap.pdfIn PDF document text
    • http://tks-forever.com/upload/2021/09/03/file/jatovetakusudobimozave.pdfIn PDF document text
    • https://castilloexterior.es/ckfinder/userfiles/files/dukorojiboriloduzirulator.pdfIn PDF document text
    • http://phutungtdc.com/upload/files/82843982913.pdfIn PDF document text
    • http://tid.vn/upload/files/jegabi.pdfIn PDF document text
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/ukts17clh4h0iq5ed58i974174/43497760212.pdfIn PDF document text
    • http://vitccorp.com/uploads/userfiles/file/kubigegotalenagexu.pdfIn PDF document text
    • http://sieckultury.pl/wp-content/plugins/super-forms/uploads/php/files/1acd35425d55100ec324b887afdf5102/97277823460.pdfIn PDF document text
    • https://renfrewareahealthvillage.ca/ckfinder/userfiles/files/tulerajiviluzuxada.pdfIn PDF document text
    • http://skolicka.eu/foto/images/file/kasowewumabusasapuwuwejo.pdfIn PDF document text
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/bc3f264356245ee9973198aa39484198/64634936826.pdfIn PDF document text
    • https://www.opsclown.it/ckfinder/userfiles/files/xurujuzepujepofifedug.pdfIn PDF document text
    • https://ventadeterrenosagricolas.com/userfiles/file/8286205741.pdfIn PDF document text
    • http://www.urbanwaterways.info/files/54727535677.pdfIn PDF document text
    • http://hcbarrett.com/user_area/file/16459747968.pdfIn PDF document text
    • https://stoneappeal.in/FCKeditor/file/duduwewewim.pdfIn PDF document text
    • http://currycornersugarland.com/admin/images/file/wirafukoxerumepubexi.pdfIn PDF document text
    • https://mps-india.com/userfiles/files/jujidu.pdfIn PDF document text
    • http://sotel-perm.ru/site/file/30201356224.pdfIn PDF document text
    • http://kleinschadenexperte.de/userfiles/file/gevalasoriz.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_off0000bd31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBD31 10872 bytes
SHA-256: 0f4f810a485b41a3873dee48bd5e4a62733265afc22d9e8403b52ab32b7505ef
font_01_sfnt_off0000d68c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD68C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ee9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE9E 16692 bytes
SHA-256: ca70de3ee3bf8394bc426c2a49e534db8c236f2f8988496803e1db10e9320357