Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5b359956ffefd04…

MALICIOUS

PDF

83.0 KB Created: 2021-09-13 12:37:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 1e4b5e4372ad442e5fd1926a9eea08a7 SHA-1: 5c404effeaed3316b6cf3b9ada64fc85f11c6c35 SHA-256: c5b359956ffefd04ad8988f3f912af10aef83846a2d995883c25f485142188b3
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, indicative of a link farm. The 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics confirm this behavior. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to lure users to phishing sites or download further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 https://atputasbaze.lv/images/userfiles/files/lilinu.pdf In PDF document text
    • http://roycraft.ca/userfiles/file/76995084744.pdfIn PDF document text
    • https://www.icicle-mountaineering.ltd.uk/ckfinder/userfiles/files/guwerixin.pdfIn PDF document text
    • http://www.andreapondika.cz/file/relaganewebugupuduzefok.pdfIn PDF document text
    • http://gamax-motor.cz/data/dokumenty/sapowikexexipas.pdfIn PDF document text
    • http://abwrosedale.com/uploads/files/44705833681.pdfIn PDF document text
    • http://goodmax.ru/i/files/79265381525.pdfIn PDF document text
    • https://discovery99.com/userfiles/file/gatase.pdfIn PDF document text
    • http://elosc.com/upFile/file///ITX202109101517327619.pdfIn PDF document text
    • http://asu.com.vn/wp-content/plugins/super-forms/uploads/php/files/72qi2co4b1v3q3pqgevgibc74h/jerufekesulemesalan.pdfIn PDF document text
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613290401ab6c---74749378268.pdfIn PDF document text
    • https://www.newhorizonscrisiscenter.org/ckfinder/userfiles/files/fipumov.pdfIn PDF document text
    • http://vakantie-noordlimburg.nl/ckfinder/userfiles/files/garemusedupijukus.pdfIn PDF document text
    • https://yapluka-services.fr/userfiles/file/sokanofoneju.pdfIn PDF document text
    • https://tonere.shop/app/webroot/files/userfiles/files/62709304177.pdfIn PDF document text
    • https://gyn-koe70.de/obrazky/file/renivuturabadi.pdfIn PDF document text
    • https://iword.de/userfiles/file/5125959081.pdfIn PDF document text
    • http://specialcats.nl/media/files/60026895276.pdfIn PDF document text
    • https://www.weldcor.ca/public/ckfinder/userfiles/files/gunasikoro.pdfIn PDF document text
    • http://web-news.eu/www/pkpar/userfiles/file/8320805573.pdfIn PDF document text
    • http://aybar-gallery.com/userfiles/files/73060603749.pdfIn PDF document text
    • https://www.sir.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613a861c07b3e---78235042719.pdfIn PDF document text
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613decd0c9e1f---tafomonife.pdfIn PDF document text
    • http://old.arcnet.org.tw/ckfinder/userfiles/files/11380419770.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=business+simulation+games+iosPDF 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_off0000e353.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE353 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fb6a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB6A 10504 bytes
SHA-256: 048ae810dfd995ede7500fd65e271b0951650c0b2e25d48c80d34ec65224f044
font_02_sfnt_off00011357.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11357 16468 bytes
SHA-256: ef412a39cf3d0539f7d8bdd573c3b72289ab8050aeace8b33bcbbf16c278c9ff