Malicious PDF — malware analysis report

Static analysis result for SHA-256 bcf838fc7928eb42…

MALICIOUS

PDF

70.0 KB Created: 2021-09-27 01:35:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: f2343bdab2808c9e9fb8c5b36f3bbf67 SHA-1: b74f4ff3d9d06c3bc988a55c73aa0af441b21336 SHA-256: bcf838fc7928eb425c7d90f74a14e4b892a6d646e028b65259a10fb7f9ba9245
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF containing numerous embedded URLs, many of which are hosted on disposable domains and appear to be part of a link farm. The heuristic 'SE_CALLBACK_LURE' suggests a phishing or scam context, and the ML classifier strongly flags it as malicious. The presence of external URIs and the overall structure indicate an attempt to redirect users to malicious content, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9916

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://oniceh.ru/uplcv?utm_term=gta+5+for+mobile+download+free PDF link annotation
    • http://vhz.cz/user-files/1359263069.pdfIn PDF document text
    • http://myesen.life/userfiles/file/44239520209.pdfIn PDF document text
    • https://petribax.nl/userfiles/file/31401831395.pdfIn PDF document text
    • http://jowinbio.com/upload/files/202109200159129252.pdfIn PDF document text
    • http://advairtech.eu/assets/userfiles/file/zivapifiturinuw.pdfIn PDF document text
    • http://sysquare.com/UserFiles/files/jusokaxuxe.pdfIn PDF document text
    • http://primeasset.hu/fileok/file/86983675860.pdfIn PDF document text
    • http://fijiembajak.com/uploads/ck_uploads/files/80407508179.pdfIn PDF document text
    • http://smartwealthhk.com/userfiles/96342687932.pdfIn PDF document text
    • https://groupunsur3.com/contents/files/vafuvazodidinumom.pdfIn PDF document text
    • https://riosemarescentrodemergulho.com/ckfinder/files/jogiroz.pdfIn PDF document text
    • http://xn--hy1bt45apoap01a.net/jangheung/userfiles/file/bewefagudaxo.pdfIn PDF document text
    • http://techbis.pl/files/file/fejinukukowutaxezubezu.pdfIn PDF document text
    • https://am-system.eu/ckfinder/userfiles/files/55086171782.pdfIn PDF document text
    • http://www.cargeacrew.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614fb6abb7162---tewus.pdfIn PDF document text
    • http://flexa.cz/docs/file/pipaxeketuzoxiviwek.pdfIn PDF document text
    • http://hosungtour.com/FileData/ckfinder/files/20210906_EA61B7C1DE86D723.pdfIn PDF document text
    • https://mi-stores.com/basketballtotaal/images/editor/file/wuvotemasufijipamijok.pdfIn PDF document text
    • http://cisseo.net/userfiles/files/60166163852.pdfIn PDF document text
    • http://eqsport.nl/userfiles/file/tazeporugomopaw.pdfIn PDF document text
    • http://lussoleathertiles.com/test4/EDITOR/example/v2/userfiles/file/24139955247.pdfIn PDF document text
    • http://mosme.org/uploadfile/files/68085316730.pdfIn PDF document text
    • http://monteconsultants.com/image/upload/File/dopubefosamijoku.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613629e108e61---63083663362.pdfIn PDF document text
    • http://soeurs-scjboran.fr/soeurs/upload/files/76605507381.pdfIn PDF document text
    • http://shriramashramps.org/userfiles/file/69599523230.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_off0000b3f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3F7 14836 bytes
SHA-256: ceacefb354727709f20e20beb15e725acd3bccbb2a632ecd313a3d677c5ef826
font_01_sfnt_off0000d936.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD936 10744 bytes
SHA-256: 8d9ca18ef0cb1d9c26f7b242a8c76e02d1a4b4447edeffb4142ad52c51f2f798
font_02_sfnt_off0000f205.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF205 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1