Malicious PDF — malware analysis report

Static analysis result for SHA-256 b51d1617015d67a1…

MALICIOUS

PDF

81.3 KB Created: 2021-09-18 10:16:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 4ff16dc02b23a9c901536942deee49da SHA-1: 3d7cba91301b8c36e3bb1856791dafb3ce15fae4 SHA-256: b51d1617015d67a1e483b9417e37b4850f7fd3b67cd7f70fe75ac8369c8b6d59
156 Risk Score

Malware Insights

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

The PDF contains numerous links to external websites, many of which are hosted on compromised or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. The presence of a compromised WordPress upload link further supports the malicious nature of the hosted content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://gites-les-bardots.com/userfiles/file/litamemonukibum.pdf In PDF document text
    • https://paulogomeslda.com/userfiles/file/85723857391.pdfIn PDF document text
    • http://www.alfapilates.pl/upload/file/24184152268.pdfIn PDF document text
    • http://mirsistem.com/depo/sayfaresim/file/40151758172.pdfIn PDF document text
    • http://elesi.eu/fichiers/files/leduxunaloxexigizozibol.pdfIn PDF document text
    • http://urbancollab.com/userfiles/Proj_Name/files/kasekej.pdfIn PDF document text
    • https://htfcompact.com/wp-content/plugins/super-forms/uploads/php/files/54bcf43ba8de080ab29ff0595539cd81/duxufej.pdfIn PDF document text
    • http://posicert.com/upload_fck/file/2021-9-16/20210916101053864875.pdfIn PDF document text
    • https://best-label.com/upload/files/badarew.pdfIn PDF document text
    • https://ivfnna.gr/wp-content/plugins/super-forms/uploads/php/files/80ff3c286a7cecd710f67037636d47e5/53855618932.pdfIn PDF document text
    • http://gourmethousemacau.com/UploadFilesfile///90813276280.pdfIn PDF document text
    • http://www.plain-pied.com/editeur/ckfinder/userfiles/files/dujenubepotopewex.pdfIn PDF document text
    • http://ksiclubbiz.ksiclub.org/svnprojects/DHD/Source/images/files/89680093205.pdfIn PDF document text
    • http://aaexpansionjoint.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139cb6c36fd8---59146970989.pdfIn PDF document text
    • https://megacook.pt/site/upload/file/92763554888.pdfIn PDF document text
    • https://gedayapi.com/userfiles/file/xukajepefufazivulovuxa.pdfIn PDF document text
    • http://form4concrete.ru/pics/cont/file/34142434540.pdfIn PDF document text
    • http://nj-rshb.com/v15/Upload/file/202198137204256.pdfIn PDF document text
    • https://rpaxis.net/userfiles/file/52071117097.pdfIn PDF document text
    • https://cambodiadriverservice.com/userfiles/file/wakofigotilumazokebane.pdfIn PDF document text
    • http://roomyab.ir/basefile/roomyabir/files/kimidokamuvumugafizilikib.pdfIn PDF document text
    • https://spbmworld.com/anaeter_capital/siteadmin/userfiles/files/61247623067.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=authentic+task+meaningPDF 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_off0000dccf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCCF 16692 bytes
SHA-256: f1e6bda8cd51c3543e3a8d91106773dcc98dea45913f6e185599fff802855f84
font_01_sfnt_off000107a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107A0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011fb7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11FB7 10584 bytes
SHA-256: 55169107ec37da0b07d28e547944678f176a23466d7b5157fb2a919d0c413dd0