Malicious PDF — malware analysis report

Static analysis result for SHA-256 c4131ca63824af4a…

MALICIOUS

PDF

78.6 KB Created: 2021-09-02 07:01:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 635deaede94be8b13c067a82f7c567a9 SHA-1: d54eb49fb59973f794b8ebc44139f85c6662acae SHA-256: c4131ca63824af4ae2f8d8a7b88eff3d1cc1d370c35bb2b91f15222009af4e86
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, presenting numerous URLs that point to compromised CMS uploads and disposable hosting, likely to lure users into downloading further malware or engaging in phishing activities. The PDF structure and embedded links are consistent with a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://banglatalkies.com/dynamic-images/cms/file/veguwamifikewe.pdf In PDF document text
    • http://fw-simple.com/uploads/files/22682488993.pdfIn PDF document text
    • http://lapenya.cat/imgjovesnaves/file/6502161284.pdfIn PDF document text
    • http://www.dj-csnl.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607c7c89bd49e---vaveguxaravojur.pdfIn PDF document text
    • https://motionslam.com/wp-content/plugins/super-forms/uploads/php/files/1e4d30a7a9f072e6b33b17ee47985494/85001652609.pdfIn PDF document text
    • http://erfolgsapp.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ec9f29adf0a---pixuxuzefaxe.pdfIn PDF document text
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/16124489334c9f---vefexutibopaxawepupugisi.pdfIn PDF document text
    • https://castilloexterior.es/ckfinder/userfiles/files/82889982422.pdfIn PDF document text
    • http://dawahcity.com/userfiles/file/6704020411.pdfIn PDF document text
    • https://sketchup360.vn/wp-content/plugins/super-forms/uploads/php/files/mofmr67nic4ittjt8utsbggti9/50427342673.pdfIn PDF document text
    • https://winston-woodward.com/wp-content/plugins/super-forms/uploads/php/files/865c1dee098c4634a69f52700b91ddba/nesiniregoj.pdfIn PDF document text
    • http://www.zopfitravel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608249a91ab32---87064797984.pdfIn PDF document text
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b56f2225dc4---repitolulopibuse.pdfIn PDF document text
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/161003674c0a63---warosokibimi.pdfIn PDF document text
    • https://sasalidayanisma.org/uploads/file/fiwofozuwutozel.pdfIn PDF document text
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091c51c12edb---givaxixorawasudemaviruza.pdfIn PDF document text
    • http://autovoda.ru/upload/files/85378234769.pdfIn PDF document text
    • http://ballmillfactory.com/d/files/59410856985.pdfIn PDF document text
    • https://westhigienia.hu/editor_up/jujimipevubep.pdfIn PDF document text
    • https://onderdurdu.com/upload/ckfinder/files/49222022515.pdfIn PDF document text
    • https://k9-warrior.com/wp-content/plugins/super-forms/uploads/php/files/nd1toahpidpek22n23i6p3ihek/monilutezege.pdfIn PDF document text
    • https://salvamontbihor.ro/app/webroot/files/userfiles/files/76902617921.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=earth+science+regents+2012+answersPDF 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://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_off0000d060.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD060 10704 bytes
SHA-256: 09d6da6a536fc83bf17c7a2fa3ee39eeacec01739bb94efb889abc72c41e68eb
font_01_sfnt_off0000e918.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE918 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001012a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1012A 17680 bytes
SHA-256: c18b1adb5a531248ab5b1d7f5ac4139a39b36d3553c402ad269cc5c1777a0c18