Malicious PDF — malware analysis report

Static analysis result for SHA-256 855880540bb7088c…

MALICIOUS

PDF

76.2 KB Created: 2021-09-04 02:49:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 02dc7632c3e2033119520b85f0dc8029 SHA-1: 00dd60c2b73aff3e9ea5452bc4c0104121aa1cb5 SHA-256: 855880540bb7088c0d4ed6e9e3630540e06bf65595ded945fa33725232f8a79b
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, many pointing to compromised CMS uploads and disposable hosting, suggesting a phishing or malware distribution attempt. The ClamAV detection and ML classifier strongly indicate malicious intent, likely to trick users into downloading further malicious content. No scripts were extracted, but the PDF structure itself is indicative of a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 7

  • 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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://ambulatorioveterinariosismondi.eu/file/10018854194.pdf
    • http://www.chicagoalphas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ede1ab0f3f---84437908515.pdf
    • http://rideco.hu/upload/file/resadurefovimujemavujazo.pdf
    • http://karunb.com/UpLoads/files/91194587433.pdf
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a734b563e4b---41210110002.pdf
    • https://izometal.net/mm/file/mufawopiku.pdf
    • http://slbreakingnews.com/ckfinder/userfiles/files/xupakogotoxopokubizozetij.pdf
    • https://amartzon.store/wp-content/plugins/super-forms/uploads/php/files/8276b5335e8c66d8cacdefdced7a0357/79402768738.pdf
    • https://gangwontaxi.com/FileData/ckfinder/files/20210903_7D4903306D479184.pdf
    • http://aolisenjiancai.com/data/files/8636122830.pdf
    • https://electrabicycles.pl/app/webroot/uploads/file/16255978449889.pdf
    • https://skyzoan.com/cake/beta/userfiles/file/bigakozedupivusano.pdf
    • http://pansophers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607755e855d19---63289313208.pdf
    • https://www.saltriot.com/wp-content/plugins/super-forms/uploads/php/files/5fe6e442be404c983e6b821801ce130a/85682767298.pdf
    • http://macap.nl/app/webroot/files/userfiles/files/35649591946.pdf
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c98fee4b94a---raxomowododiradovarowo.pdf
    • http://bdata.vn/upload/files/7435911904.pdf
    • http://gentlemensquartersbarbershop.com/wp-content/plugins/super-forms/uploads/php/files/17be53d9480f2bca133f2b54e8f0b660/34017695331.pdf
    • https://www.tctnanotech.com/wp-content/plugins/super-forms/uploads/php/files/137e755ce5809e7312ff6d0127dc7e04/zazavazaninoduzozoju.pdf
    • http://sapaethnic.com/webroot/img/files/gekixupubunelozelogov.pdf
    • http://cdmatik.com/uploads/file/28828052471.pdf
    • https://www.d-table.com/wp-content/plugins/super-forms/uploads/php/files/5c84da367c8dcfb30e1011d39032f820/matopanotodobazamasiruvol.pdf
    • https://valenciamaids.com/userfiles/files/zazurebukin.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=calendario+julio+agosto+2019+pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c1b8.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC1B8 16792 bytes
font_01_sfnt_off0000d9cf.bin
b3a7772e7fa3f76bf45a2270c50e210953649b5149452091512d964ab75b1cbd
pdf-font-stream PDF embedded font (sfnt) at offset 0xD9CF 11396 bytes
font_02_sfnt_off0000f49c.bin
14d35c8908da366c50686ed81243e1720dbe6d962051cf19dbfa8b62894a0984
pdf-font-stream PDF embedded font (sfnt) at offset 0xF49C 18032 bytes