Malicious PDF — malware analysis report

Static analysis result for SHA-256 3a497a2b7f4d9cd3…

MALICIOUS

PDF

91.1 KB Created: 2021-07-15 22:22:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: df6c5a018cf3c18b1faa12e07a50c126 SHA-1: 21772a33d6a1435f3efc6153d79702afcdf02540 SHA-256: 3a497a2b7f4d9cd37b87f444d36c418fa617ff9a4fbd247377a8e10cc2ec6630
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised WordPress upload directories and disposable hosting, suggesting a phishing or malware distribution scheme. The document body was unreadable, but the presence of numerous external links strongly supports the link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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.lumisolar.pe/wp-content/plugins/formcraft/file-upload/server/content/files/160b4521500b5d---37942597458.pdf In PDF document text
    • http://matrixuniverzum.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1607e1921a6548---kofelamedagugilitunuv.pdfIn PDF document text
    • http://carefirstwalkathon.com/clients/8/89/89514deb4c0e8807eb046cac28c4977f/File/jamif.pdfIn PDF document text
    • https://www.adcgrain.com/wp-content/plugins/super-forms/uploads/php/files/80d052e139c558b48e1d44060d877757/wafugusuja.pdfIn PDF document text
    • http://www.x454.com/wp-content/plugins/super-forms/uploads/php/files/vmdie2q4q9699jnq02iibk1qo4/57380633543.pdfIn PDF document text
    • http://files.ibiza-ferien.de/file/42068970263.pdfIn PDF document text
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc4cf968ae---18712753697.pdfIn PDF document text
    • http://kiavysocina.cz/UserFiles/File/43118362987.pdfIn PDF document text
    • http://xiaohecollege.com/d/files/82380782331.pdfIn PDF document text
    • https://privatecambodiatour.com/userfiles/file/75342984358.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/bc544cead7388cad58f2c241e2aa9658/52536889811.pdfIn PDF document text
    • http://skolicka.eu/foto/images/file/82693349837.pdfIn PDF document text
    • https://www.popcaffe.it/wp-content/plugins/super-forms/uploads/php/files/abfd533f09cdc7885afb6588e324db8c/50409455746.pdfIn PDF document text
    • http://zoncmswebsitebeheer.nl/files/editor/file/54459882397.pdfIn PDF document text
    • http://ydis.kr/userfiles/file/301304052610.pdfIn PDF document text
    • http://auroraenergyproject.it/userfiles/files/19043884324.pdfIn PDF document text
    • https://sakitonus.ru/wp-content/plugins/super-forms/uploads/php/files/4f8ab64a1e663ad6e4c338c82ba21d1a/58295625594.pdfIn PDF document text
    • http://www.lbf-cosmetics.com/website/wp-content/plugins/formcraft/file-upload/server/content/files/1607a422f531fd---letisuwogajej.pdfIn PDF document text
    • https://portsidestrategies.com/wp-content/plugins/super-forms/uploads/php/files/02e869ff13c8dd1db8c4f77c32e7b7b9/wegawe.pdfIn PDF document text
    • http://lirealestatelitigator.com/wp-content/plugins/super-forms/uploads/php/files/ce09e21f97dd811ab55c87b0e43d6e34/99888236445.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/160735caa35edb---94177423763.pdfIn PDF document text
    • https://www.escon.it/wp-content/plugins/super-forms/uploads/php/files/6e88b32f209b38c2159d4e23188f5399/xegavopenu.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160873d674e2a0---rovibojatezonezumunuzo.pdfIn PDF document text
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/18ebaed0ed06b8744ade32cc66113710/dowipunewurijeraxozam.pdfIn PDF document text
    • http://mega-gold.com/userfiles/files/gapisamotibalarowuv.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=never+split+the+difference+pdfPDF 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_off0000ffe7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFE7 17852 bytes
SHA-256: 93e787da428cfc850e7897d9509173a8a490d0e44e32ad20ff2eaa797999c7c1
font_01_sfnt_off00012f02.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F02 10480 bytes
SHA-256: 06048d9cab3107013305cea718784992de5dbae4a2444e49b3711956f4e68ff0
font_02_sfnt_off000146c4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x146C4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1