Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8a0264d93a10b65…

MALICIOUS

PDF

87.6 KB Created: 2021-06-28 17:07:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: cbcc678d3f9803e9769ce4b5ce13bc31 SHA-1: 42f9b618fd48025a260a6f56b0d2663dd1a07754 SHA-256: c8a0264d93a10b6586593f0f5eec29e86123d96590544db0e2389a289be139df
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, indicating it likely exploits a vulnerability or contains malicious content. Heuristics identified it as a link farm pointing to compromised CMS uploads and disposable hosting, suggesting a phishing or malware distribution scheme. While no scripts were directly extracted, the PDF structure and embedded URLs strongly imply an attempt to redirect users to malicious sites, potentially for further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9952

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://vgi-vn.vn/app/webroot/img/files/gekexisilesufu.pdf
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3321da8711---zowudob.pdf
    • http://broadviewlibrary.org/uploaded_bvlib/file/gixemudunaxujut.pdf
    • https://t4g.nasscomfoundation.org/wp-content/plugins/super-forms/uploads/php/files/5mm70irrcgvmm1m33pa40hd0r6/leremubexijiki.pdf
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/4k8l2e0201kou1ffb2bm5huqn6/rejoxawuxawo.pdf
    • https://lllk.ru/wp-content/plugins/super-forms/uploads/php/files/aa7399846093307904526f201184c3f9/linamotawupopagosunipu.pdf
    • https://www.mds-horizons.com/upload/files/17021646492.pdf
    • https://hsegroup.ru/wp-content/plugins/super-forms/uploads/php/files/ttich81dc18enk6ecb5u8g8hf7/42963187336.pdf
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608a7883b91c2---46909851692.pdf
    • https://nscs.org/wp-content/plugins/super-forms/uploads/php/files/d621b01038bc35a7d14d25ac51f01a7a/29289329557.pdf
    • http://www.ambredore.com/wp-content/plugins/formcraft/file-upload/server/content/files/160866253a22dc---sulitiwajubekisibiwipofi.pdf
    • http://alpanelektrik.com/depo/sayfaresim/file/4285542207.pdf
    • https://landbar.com/upload/files/keniwiwutojanunomowazipi.pdf
    • http://srihemkuntsahibfgp.org/hemkunt/userfiles/file/pawenujezajagasikedefofi.pdf
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609b82971be60---degajujepaja.pdf
    • http://ecbpolska.pl/wp-content/plugins/super-forms/uploads/php/files/7db9612c8d73de2b7dff00973f1941e6/35042030060.pdf
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/77fb527024923bb5a7943cd7461623f5/guverepidavufavodogowuvik.pdf
    • http://leoclubmarsala.it/userfiles/files/wizigizorur.pdf
    • https://edukiya.com/wp-content/plugins/super-forms/uploads/php/files/63820575958b7293e1d395543485f214/59299893114.pdf
    • https://www.couleurs-et-jardin.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16091afd76652c---rumesebadejunazegupoziw.pdf
    • http://geodez.com/pliki/file/47392035449.pdf
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a241621389---rodeginewibufotuvebojinob.pdf
    • http://zonweringbelgie.com/ckfinder/userfiles/files/80479987200.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=structure+of+formal+report+writing
    • 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_off0000f586.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF586 16792 bytes
font_01_sfnt_off00010d98.bin
4a14da0d8be981859916e224a158276fddfdfecb3043396ed2c67f3656db0159
pdf-font-stream PDF embedded font (sfnt) at offset 0x10D98 16388 bytes
font_02_sfnt_off000137ec.bin
62176fa435894eec6a5dcd1907116619e0d8cf78f1723e2fef6f1d770855151c
pdf-font-stream PDF embedded font (sfnt) at offset 0x137EC 10916 bytes