Malicious PDF — malware analysis report

Static analysis result for SHA-256 1d081bcd9f6e2c73…

MALICIOUS

PDF

71.9 KB Created: 2021-10-02 18:31:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ae62ed35c879bdc2cfa6423e45e3f5c3 SHA-1: e639bed3cc0289145a70777b52fed8b0b54312df SHA-256: 1d081bcd9f6e2c732513a3bde569e49eaad0e34ef5ac6dcea55bdf1a0a0c7267
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a ML classifier and ClamAV, indicating it is likely a phishing or trojan delivery mechanism. The document functions as a link farm, directing users to various external websites, some of which are hosted on compromised CMS upload directories. The presence of numerous links on disposable hosting further supports a malicious intent, likely to distribute further malware or phish for credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://chongthamphucthang.com/images/news/files/30450426656.pdf
    • https://ewms.vn/wp-content/plugins/super-forms/uploads/php/files/6ag261boch6iub5epr86l5bm34/fupamefozudile.pdf
    • https://inchiriereelicoptere.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16147ff6f90a0a---vukumero.pdf
    • https://handientu.vn/userfiles/file/91015150392.pdf
    • http://joltiy.ru/uploads/files/16975023348.pdf
    • https://eliteswimmingpoolsinc.com/wp-content/plugins/super-forms/uploads/php/files/laed8rla8jt2jdtffdmk5iirh7/60138118309.pdf
    • http://cdmvt.cz/sites/default/files/87403941990.pdf
    • https://www.rosebankprimary.co.za/inc/ckfinder/userfiles/files/10601929104.pdf
    • https://clearpatth.com/userfiles/file/bibawebuzuf.pdf
    • http://zhouzhuank.com/v15/Upload/file/202194235239955.pdf
    • http://mdfgiare.com/upload/files/lawaroniborofanetasepor.pdf
    • https://behbehaniprojects.com/uploads/files/voronuv.pdf
    • http://technestudio.eu/userfiles/files/xotij.pdf
    • https://mygoaltv.org/ipp/images/uploads/files/63717903667.pdf
    • http://majedalkarkhi.com/pics/file/9231820875.pdf
    • http://nhasachthunam.com/upload/files/67158067540.pdf
    • http://isagenixmakessense.com/ckfinder/userfiles/files/68474230746.pdf
    • http://qianshunqs.com/admin/upload/36806401604.pdf
    • http://tichdiem.surecare.vn/uploads/userfiles/file/92250161542.pdf
    • https://tattica.byespresso.com/app/webroot/files/upload/files/24269128836.pdf
    • http://hunting.kg/userfiles/file/701278160.pdf
    • http://exmar.it/foto_fck/file/64803876297.pdf
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/d115d02810b3f575353466393e65cc6a/foxom.pdf
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a699878fc9---remogudegopirazutabora.pdf
    • http://www.recko.ru/ckfinder/userfiles/files/79177541194.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=high+potential+development+programs
    • 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_off0000b445.bin
2864254a9e0cd04c107b5186d0e93e6def69da5c4789e025755cec9207356eec
pdf-font-stream PDF embedded font (sfnt) at offset 0xB445 10896 bytes
font_01_sfnt_off0000cd09.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCD09 16792 bytes
font_02_sfnt_off0000e51b.bin
b45621e2c2a4eeb8e44b4c8458fe2ada2063d9c57ade03ec9d68f72ddb7ba46d
pdf-font-stream PDF embedded font (sfnt) at offset 0xE51B 17524 bytes