Malicious PDF — malware analysis report

Static analysis result for SHA-256 87b37b5707af42d5…

MALICIOUS

PDF

71.6 KB Created: 2021-09-22 18:08:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 56dd88f6c652c42fc8b5014b09f3ef16 SHA-1: 71c546ab88f6c5e3ad3b26771a902df8426bdf52 SHA-256: 87b37b5707af42d57b8a1cb317368da34ce2ef093fac1325b345f98a9a1bf541
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs pointing to a link farm, suggesting a tactic to manipulate search engine results or distribute further malicious content. While no scripts were explicitly extracted, the PDF structure and heuristic firings suggest it may leverage embedded JavaScript for malicious actions, such as redirecting users to these external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://buddhaart.in/userfiles/file/jaxufidamitileli.pdf In PDF document text
    • https://cebrium.ssnn.ro/images/55383924145.pdfIn PDF document text
    • https://pomtco.com/technical/files/file/8537048780.pdfIn PDF document text
    • http://thuexedanang247.com/uploads/image/files/88265181600.pdfIn PDF document text
    • http://guide-eq.com/userfiles/file/20210912121239_kr4gxp.pdfIn PDF document text
    • http://shortguycentral.com/ck_uploads/files/dikufetipesakixozebimopen.pdfIn PDF document text
    • https://ph789.com/pinhsuan/files/file/65445829574.pdfIn PDF document text
    • https://jbdclothiers.net/emailer/userfiles/file/zuripopeliwekim.pdfIn PDF document text
    • http://wasserentkalkung.at/ckfinder/userfiles/files/23628008606.pdfIn PDF document text
    • http://gekon.net/userfiles/file/97358742293.pdfIn PDF document text
    • http://airzo.net/userData/board/file/nurarikafobisutagugiroja.pdfIn PDF document text
    • https://groupekineconcept.com/userfiles/file/4380072870.pdfIn PDF document text
    • https://fgcrubochi.com.ng/ckfinder/userfiles/files/xeredabevarixomo.pdfIn PDF document text
    • https://kamhosting.nl/ckfinder/userfiles/files/voterudelamozupanegusijas.pdfIn PDF document text
    • https://firesystem.ro/imagini_ws/31675565314.pdfIn PDF document text
    • https://funcarele.com/ckfinder/userfiles/files/70178799558.pdfIn PDF document text
    • http://getawaynewzealand.co.nz/wp-content/plugins/formcraft/file-upload/server/content/files/1614425d34c8b0---nipugevesexubegibokutan.pdfIn PDF document text
    • http://asja-doll.ru/userfiles/file/37596787685.pdfIn PDF document text
    • http://s8radziejowice-paszkow.pl/userfiles/file/ninevojire.pdfIn PDF document text
    • http://ambvetsanprospero.eu/userfiles/files/matakegekotebowodiva.pdfIn PDF document text
    • https://amkboiler.com/wp-content/plugins/super-forms/uploads/php/files/hhjrbckr4mghir4dkpg34b1npe/vutekixumo.pdfIn PDF document text
    • https://atrax.hr/files/7997622703.pdfIn PDF document text
    • http://gopherandsquirrelcontrol.com/admin/images/file/levegelugebedojag.pdfIn PDF document text
    • http://poiskvod.ru/images/file/sivoxonovexelagu.pdfIn PDF document text
    • https://mosaicopeoplecorporation.com/ckfinder/userfiles/files/8774380538.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=tubidy+mp4+juicePDF 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_off0000b8c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8C9 10404 bytes
SHA-256: 8a494fc8121c3ad16526980b930a264f8786690ef1fb2207cee5698f9e20ea54
font_01_sfnt_off0000d018.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD018 16044 bytes
SHA-256: cea38000457c50c8953d83258e1d57f2b9c09b1abfb433ec08f4055e82e5c9fa
font_02_sfnt_off0000f8c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8C2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1