Malicious PDF — malware analysis report

Static analysis result for SHA-256 3aa8b947d1ccc003…

MALICIOUS

PDF

87.6 KB Created: 2021-07-30 17:44:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: f5dadf1f5a7cba344a28e93fb02aae57 SHA-1: 9348f067f38774bd24305bf6821b448c5619459e SHA-256: 3aa8b947d1ccc003b6c5c118c89298fd55d5779c6c32d28b3d05543d831aec80
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, pointing to multiple compromised WordPress upload directories and disposable hosting sites. The embedded URLs, despite some being marked benign, contribute to the overall malicious intent of directing users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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 http://musorcentrum.hu/files/article/file/17388363546.pdf In PDF document text
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/pd2g1mssqr2gkhjksmps3qcnj7/1928009750.pdfIn PDF document text
    • http://www.520amis.com/upload/files/63182668582.pdfIn PDF document text
    • http://chocolatycakes.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095a312c6d57---41640388572.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/1609c70397645d---mivevezexawufu.pdfIn PDF document text
    • https://www.marbelitesa.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160a5bd5929b23---11711597382.pdfIn PDF document text
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607125c2da52f---74383036885.pdfIn PDF document text
    • https://vallejardin.com/wp-content/plugins/super-forms/uploads/php/files/1640130c42131ecfa8fcda247564a603/77313986722.pdfIn PDF document text
    • http://www.rkcomdesignservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c87db3f429---tigalevogosopasafinukixux.pdfIn PDF document text
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/f7747534e067b65e5fc11920b04e6118/juwepotosixuvinexo.pdfIn PDF document text
    • http://sanitaerprofi.ch/fckeditor/editor/images/file/danakemowejujugesu.pdfIn PDF document text
    • https://autotrilogy.com/wp-content/plugins/super-forms/uploads/php/files/dc86ad974843e346eded4fd577f1c38c/janunul.pdfIn PDF document text
    • https://www.crossfitparamaribo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aca5d1ee937---70735815304.pdfIn PDF document text
    • http://shukokai-voves.fr/userfiles/file/jamuzagusutifarosupukamux.pdfIn PDF document text
    • http://entone.es/wp-content/plugins/super-forms/uploads/php/files/fb21d565de4943960ff11c084b4f958f/tapisiripurefolobosidi.pdfIn PDF document text
    • http://grani-tonkogo-mira.ru/wp-content/plugins/super-forms/uploads/php/files/51c54025827687de49c9c97cf928e46f/69814788143.pdfIn PDF document text
    • http://cuhs1981.com/clients/8/82/82ca37c076ec4232796cb58ed009bb3a/File/xowikorosog.pdfIn PDF document text
    • http://kibbkw.com/uploads/files/nogegapeleletofu.pdfIn PDF document text
    • https://www.dyna-tech.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160d8412ba4893---20295967749.pdfIn PDF document text
    • http://plenaadoracao.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160884e3325eed---jiwaponatavadano.pdfIn PDF document text
    • http://www.nbrownies.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160e2ddd081a4e---mezenabi.pdfIn PDF document text
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160991c13f200c---34657644854.pdfIn PDF document text
    • http://castrolmintabolt.hu/images/upload/file/33641937900.pdfIn PDF document text
    • https://reazfarah.com/ckfinder/userfiles/files/12827118960.pdfIn PDF document text
    • http://peaceinsrilanka.lk/userfiles/file/3466589036.pdfIn PDF document text
    • https://pametnidom.hr/pametne_kuce/userfiles/file/didiwidiwonixiwelusodom.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=is+the+servsafe+certification+the+same+as+a+food+handlers+cardPDF 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_off0000f1fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1FA 17232 bytes
SHA-256: 3a51872ddd223f3e88b6601ebca8f452a3ffa883aa3177e30aea7cd0d2b569a9
font_01_sfnt_off00011f31.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F31 10760 bytes
SHA-256: bc7f44b09986a072a68e66099bb3d3b93ee064a5dd9a04b8c87c227c26489109
font_02_sfnt_off000137cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137CB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1