Malicious PDF — malware analysis report

Static analysis result for SHA-256 6b555a9b3fca1a99…

MALICIOUS

PDF

91.6 KB Created: 2021-07-22 02:51:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0629dc5f34dd7a9baaf98f2f38a8d9fb SHA-1: 5c967716a3535fec04e2ccc8d49a849a7677f9a7 SHA-256: 6b555a9b3fca1a991f8bcfae740664902e2c5ceb275cd22a6ae927734b7dbf33
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 WordPress sites, indicating a link farm designed to obscure the final destination. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery through these links. The document body is heavily obfuscated and unreadable, providing no direct content clues, but the heuristic firings and URL analysis are sufficient to infer a malicious link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9937

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://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160cd1ed75f4fe---33291301331.pdf
    • http://kiemtoanhaiphong.vn/upload/files/65758561871.pdf
    • https://cremeconferences.com/wp-content/plugins/super-forms/uploads/php/files/bfb3104683ae6907aff415d7517022c6/kozudolas.pdf
    • https://qqhanoman.com/contents//files/gogogesenivezijuseg.pdf
    • https://sckstone.com/wp-content/plugins/super-forms/uploads/php/files/c98e5b380739f22d83eb744015e30308/78399222437.pdf
    • http://lifestyleufa.ru/wp-content/plugins/super-forms/uploads/php/files/baea3077fc6f9edf16e1f320244bd348/kugudiwajosar.pdf
    • https://aawyx.com/sites/default/imageuser/file/68307139071.pdf
    • http://protech.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/1606d81a406e67---40294396064.pdf
    • http://china-zzld.com/uploadfile/file///2021070515091338.pdf
    • http://shinserviceodi.ru/wp-content/plugins/super-forms/uploads/php/files/ba1be53b99f94ccccb8b2293916408da/61238093230.pdf
    • https://www.accidentinjurylascruces.com/wp-content/plugins/super-forms/uploads/php/files/jdi39ohk0j14r8hgljc74g03l4/xigirovazudagi.pdf
    • http://www.k-24.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606cbf7e3d35f---2764721036.pdf
    • http://xpressup.com/userfiles/file/45770520199.pdf
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607c2dc69cfa8---8812614016.pdf
    • http://sbhs1967.com/clients/8/89/8985ce50e7417da620f75e2af787291b/File/24320402634.pdf
    • http://www.cargeacrew.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160d7d1adcde8f---74874986161.pdf
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/d688b07bbabdfb78c9116dbe17c2b28c/kebononixixul.pdf
    • https://jjmassociates.com/wp-content/plugins/super-forms/uploads/php/files/f3c3ddae18cc137770b054dbee00208f/jufor.pdf
    • http://sys-svinding.dk/userfiles/file/soxiduwugedufakasaturo.pdf
    • http://botanicgardenscafe.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c333cf7cdb5---45136854132.pdf
    • https://sketchup360.vn/wp-content/plugins/super-forms/uploads/php/files/ljserrmpe2okfcuntsmfbg4j5j/sobezegujazona.pdf
    • https://citytrafik.nu/images/file/13496009810.pdf
    • http://china-engine.net/ckfinder/userfiles/files/zaketimitunufuzejuvogixu.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=how+to+endorse+3rd+party+check
    • 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ebd9.bin
45647295bf3e6975917d2c46c854a2f040b6d2f4fa9dfc4d8f9276b78401693b
pdf-font-stream PDF embedded font (sfnt) at offset 0xEBD9 16396 bytes
font_01_sfnt_off00010207.bin
cfe8bab2a0cd2080cddcc2f32f86c2fd63d3d54c092997c372ceed2bdfc3efd0
pdf-font-stream PDF embedded font (sfnt) at offset 0x10207 17072 bytes
font_02_sfnt_off00012eaa.bin
18e4a3292abf60effbc8a9e06b9a9da1fe2928551a214343cf38e1e52c2f39fb
pdf-font-stream PDF embedded font (sfnt) at offset 0x12EAA 10928 bytes
font_03_sfnt_off00014815.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x14815 16792 bytes