Malicious PDF — malware analysis report

Static analysis result for SHA-256 a366bb5553d672d0…

MALICIOUS

PDF

83.7 KB Created: 2021-07-13 10:32:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 32d569821e1943ea978d14d4c3d2d83b SHA-1: 1752501e8ac3623ad60ea7786fe244aa453625de SHA-256: a366bb5553d672d013105abf740fca79ab8157e6ae9a23e78d68a7911b115a05
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress sites. These sites, in turn, host further PDF files, suggesting a multi-stage lure or distribution mechanism. The primary goal appears to be directing users to malicious content via these compromised sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 https://cructi.ru/uplcv?utm_term=put+first+things+first PDF link annotation
    • https://www.acptechnologies.com/wp-content/plugins/formcraft/file-upload/server/content/files/160870e91348cb---30069932461.pdfIn PDF document text
    • http://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/03128a45fd8aa2ef401e5fb89db36b33/juruvigowomebuxuzokodanes.pdfIn PDF document text
    • http://www.zulfugar.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1608944d65d915---6084326985.pdfIn PDF document text
    • http://arunimaflavours.com/userfiles/file/zaxomugifebiboluwaxuka.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/2df2c626f6961fd9e9f016bbb8b18eb2/88266605031.pdfIn PDF document text
    • http://vilaportugal.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076b97fc83aa---sukugoxapufasowijivamisiw.pdfIn PDF document text
    • http://marcelponjee.nl/ponjeefiles/file/74648553140.pdfIn PDF document text
    • http://kinel-hunter.ru/upfiles/file/58543077874.pdfIn PDF document text
    • https://honkakuji.jp/honkakuji/images/ckfinder/files/82015258744.pdfIn PDF document text
    • https://doitsolutions.co/wp-content/plugins/super-forms/uploads/php/files/4271858c8d603d9b42c03b7280e5df33/41242036192.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c04f2be90ea---wuxakudixezobedozemunamu.pdfIn PDF document text
    • https://lecachet.fr/docs/files/xagid.pdfIn PDF document text
    • https://www.booster-p.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d6c85c4d7f3---nosonaduxesopukuxewina.pdfIn PDF document text
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/d2fdad82bb3c8a6570e72f9fcb2f3ffa/52321965458.pdfIn PDF document text
    • https://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160a46ce050ec1---65929800061.pdfIn PDF document text
    • https://razvozka24.ru/wp-content/plugins/super-forms/uploads/php/files/66daf94d422465bbc74902bc14fcad45/9969395725.pdfIn PDF document text
    • http://boothbayharborshipyard.com/userfiles/file/91258920406.pdfIn PDF document text
    • https://ofertaromania.ro/ckfinder/userfiles/files/jamarizetawikasuxuvad.pdfIn PDF document text
    • https://masterpieces-mallorca.com/wp-content/plugins/super-forms/uploads/php/files/c47a25d0e368f2b47d252cb4b16136b6/malowofezepavogowa.pdfIn PDF document text
    • http://turinhotelcompany.com/userfiles/files/jotazutavufivinofi.pdfIn PDF document text
    • http://vankouwenenmastop.nl/UserFiles/file/4058962535.pdfIn PDF document text
    • http://baanpowertrain.com/wp-content/plugins/formcraft/file-upload/server/content/files/160856a0d80a2b---60574231097.pdfIn PDF document text
    • https://skyfireconsulting.com/wp-content/plugins/super-forms/uploads/php/files/r5e97hse7euel7jaqlqadtojm4/45882993684.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc1db056e5---wegosetuxojusuxax.pdfIn PDF document text
    • 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_off0000e768.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE768 10136 bytes
SHA-256: 2c82a1317e4f6cbc4cda9f33ad131f01fcd8d7bbfd2c9637b8120f9d0a5dfa03
font_01_sfnt_off0000fdec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDEC 16864 bytes
SHA-256: f3bd6a9d83342d5ab3d4a8f53d08e773a00fb3582468a84a7d4600230cebb1f9
font_02_sfnt_off000129a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129A1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1