Malicious PDF — malware analysis report

Static analysis result for SHA-256 16f5bd00c54087f8…

MALICIOUS

PDF

70.7 KB Created: 2021-09-30 11:31:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: c37a3d0fa391fbaeeeee93db8f3f36f9 SHA-1: cd597965b150e77ad521dd88c7745a4bc44a4c55 SHA-256: 16f5bd00c54087f8c4d13eaa25aae94a468c87ac69ce1bdcd31efb8fc5b7b57d
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple external links, with several heuristics indicating it functions as a link farm hosted on potentially disposable domains. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and numerous URLs point towards an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://garglob.ru/uplcv?utm_term=homicide+tv+show+streaming PDF link annotation
    • https://chilegastronomia.cl/uploads/userfiles/files/puxoku.pdfIn PDF document text
    • http://werkkledingverkoop.nl/images/docman/files/bosaranotozij.pdfIn PDF document text
    • http://grafosaleservice.cz/images/fck_editor/file/nupexute.pdfIn PDF document text
    • http://veterinarioassociatopacinidallatorre.eu/userfiles/files/vemomarukakaxuzudozeleje.pdfIn PDF document text
    • http://bartuceviri.com/userfiles/file/41495399804.pdfIn PDF document text
    • https://globaldreamindia.com/webcms/file/vukunepixuvumi.pdfIn PDF document text
    • http://tangiahoang.com/skinkorea/Images_upload/files/pixuteveziz.pdfIn PDF document text
    • https://pointswestliving.com/ckfinder/userfiles/files/85892388928.pdfIn PDF document text
    • https://mysmartedu.com/uploadimages/files/55961589650.pdfIn PDF document text
    • https://pharmnet.cz/ckfiles/files/files/zuxevatadegojob.pdfIn PDF document text
    • https://maidintown.co.uk/wp-content/plugins/super-forms/uploads/php/files/e4a5e4f3960eecf3a923d5ead2b7390b/86863572102.pdfIn PDF document text
    • http://dezis.ru/uploads/files/14910566397.pdfIn PDF document text
    • http://ippinnudon.com/uploads/files/76614302288.pdfIn PDF document text
    • http://fotosvatba.net/userfiles/file/33730484129.pdfIn PDF document text
    • http://hongdacable.com/d/files/gudimomenalinijowu.pdfIn PDF document text
    • https://pyccenter.com/images/Upload/file/47639575629.pdfIn PDF document text
    • https://wronba.pl/uploads/wysiwyg/file/punipurudomarosovo.pdfIn PDF document text
    • http://moveisgarciadigital.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614234c1920cb---52602162373.pdfIn PDF document text
    • https://panificioilcavaliere.it/userfiles/files/54303374825.pdfIn PDF document text
    • https://photojet.bg/userfiles/file/vevivudeperowosokil.pdfIn PDF document text
    • http://thessalonikiflights.com/files/files/51822333752.pdfIn PDF document text
    • http://codienlanhminhquang.com/upload/files/rasuwafawulinixefit.pdfIn PDF document text
    • http://cerescommoditiesltd.com/Images_upload/files/pujenepiruko.pdfIn PDF document text
    • http://www.drivingschool-brno.cz/files/files/80158659959.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_off0000b23c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB23C 15820 bytes
SHA-256: ee85ccec83ef312669c59f12855f15f646d4b1cd91ba512d8c0fa8f0f488c9d9
font_01_sfnt_off0000da95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA95 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f2ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2AC 10916 bytes
SHA-256: cdd0fb87e27244c87c8f389f6f001341e7fdf78ac32ddd9227f2de18fd091336