Malicious PDF — malware analysis report

Static analysis result for SHA-256 dfbc273ec6983800…

MALICIOUS

PDF

79.5 KB Created: 2021-09-14 09:14:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: f8dfc5005fb74579384b6fc2166b7da3 SHA-1: 9c590fc47fd5f31870c182f7e1d273b77a0801ed SHA-256: dfbc273ec6983800a3fc3f72351de0bacbfb2c94ab2cea24600fc2b85759d436
156 Risk Score

Malware Insights

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

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 pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to distribute malicious content or phish users. The embedded URLs, while numerous, do not provide direct executable content, but their nature as a link farm points towards a phishing or malware distribution attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://www.sudeshnamaulik.com/fckimages/file/8874338317.pdf In PDF document text
    • http://webinaris.training/ckfinder/userfiles/publics/files/tifazijobusesugup.pdfIn PDF document text
    • http://chugguwang.com/files/fckeditor/file/55100626476.pdfIn PDF document text
    • https://www.prowallpanama.com/wp-content/plugins/super-forms/uploads/php/files/ba614fe1bdba6c0649acb65f2deb4520/vapaxojesupunabanafu.pdfIn PDF document text
    • http://keramann.ru/uploads/files/mexoxexufomurosazox.pdfIn PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613952bcdeec8---82313725554.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a8af4acea4---29117676248.pdfIn PDF document text
    • http://kcpsystem.com/userData/board/file/kutezabom.pdfIn PDF document text
    • https://argumentua.com/i/file/36188994547.pdfIn PDF document text
    • http://rydelko.pl/userfiles/file/23324364636.pdfIn PDF document text
    • http://hcm-invoice.vn/hinhanh_fckeditor/file/bujajepenufinixitut.pdfIn PDF document text
    • http://www.heksan.com.pl/file/21502578725.pdfIn PDF document text
    • http://hausdergesundheit.net/userfiles/files/zujajutikowuzi.pdfIn PDF document text
    • http://woodbridgeabw.com/uploads/files/suzufazuxatofuguwubijojo.pdfIn PDF document text
    • http://dabaizhongxue.com/upload_fck/file/2021-9-2/20210902190622486831.pdfIn PDF document text
    • http://soeurs-scjboran.fr/soeurs/upload/files/wamamigesesunipolagaraf.pdfIn PDF document text
    • http://www.vinoplaza.nl/img/upload/files/papuduwizamogisi.pdfIn PDF document text
    • http://gardatrans.com/content/Files/85478310968.pdfIn PDF document text
    • https://www.ebenisterie-burette.com/ckfinder/userfiles/files/mesijifuxibolizejemutap.pdfIn PDF document text
    • http://littlepearlbooks.in/data/eimages/file/13984530411.pdfIn PDF document text
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/fctmcap4i2aj66kuorgmi2l8uk/gelujativasidajemisonilev.pdfIn PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613fb44b8d653---faxifixidafikibe.pdfIn PDF document text
    • http://ksiclubcom.ksiclub.org/svnprojects/DHD/Source/images/files/31046417876.pdfIn PDF document text
    • https://ndmoyun.com/calisma2/files/uploads/93640698793.pdfIn PDF document text
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16131831f12ba5---nikomekimekevurivigotojir.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=harry+potter+in+russian+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_off0000d3de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3DE 17160 bytes
SHA-256: 4cd01d2e4e01f232c681fb708c7837158a258844601351972c1f5f1fb2bc582b
font_01_sfnt_off0000fff1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFF1 10652 bytes
SHA-256: 5674dc23687d772e5b9dc18aca4b1f4e8e602995469b8a528fcba652c49096f6
font_02_sfnt_off00011872.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11872 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1