Malicious PDF — malware analysis report

Static analysis result for SHA-256 856004af3c540a88…

MALICIOUS

PDF

78.7 KB Created: 2021-09-11 01:08:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: c2056fa7a9a3b0aa3a0881bf1847679a SHA-1: 7f9054dd977ef13badd6ca82e8325abdffe700ff SHA-256: 856004af3c540a8856b018aa63c7465017cdcb3221e8d329ddd27a6ffe116a27
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many of which are hosted on disposable domains and utilize UTM parameters, indicating a link farm or phishing lure. The ClamAV detection and ML classifier strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and numerous embedded URLs point towards an attempt to redirect the user to malicious content, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

Heuristics 5

  • 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.
  • 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://infrive.ru/uplcv?utm_term=apk+play+box PDF link annotation
    • http://toflight.mobi/attachment/ckeditor/files/eb038ba433970bb9e1d0d3469c338be4.pdfIn PDF document text
    • https://grupa-energia.pl/attachments/file/vegorulajusiwob.pdfIn PDF document text
    • http://ottomaniantextile.com/userfiles/file/16348860417.pdfIn PDF document text
    • https://archielectronics.com/userfiles/files/25745351581.pdfIn PDF document text
    • http://theeultimatenetworker.com/ckfinder/userfiles/files/witejuwoxewuduvub.pdfIn PDF document text
    • https://akproauto.net/nbloom/fckuploads/file/72701016018.pdfIn PDF document text
    • https://www.winsum.frl/ckfinder/userfiles/files/4811119392.pdfIn PDF document text
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613753ee7eb04---kagemagu.pdfIn PDF document text
    • http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613ba03d099b9---rerun.pdfIn PDF document text
    • http://elliptical-trainers.ru/ckfinder/userfiles/files/jevinifozin.pdfIn PDF document text
    • http://www.contectrade.hu/fckfiles/file/zukenuxoxobe.pdfIn PDF document text
    • http://kayapalinakliyat.net/file/pumalizugubavadusinutal.pdfIn PDF document text
    • http://massageindex.nl/images/uploads/55884810670.pdfIn PDF document text
    • http://shinies.ru/img/lib/file/61541759099.pdfIn PDF document text
    • https://www.afoa.org.ar/backend/ckfinder/userfiles/files/93041918023.pdfIn PDF document text
    • http://splogservice.ru/content/files/purefotesovosapafik.pdfIn PDF document text
    • https://nolimitscenter.be/peausitive/images/FCKeditor/file/rijadur.pdfIn PDF document text
    • http://mcenterdk.ru/fck_editor_files/files/gitoluvu.pdfIn PDF document text
    • http://wumag.pl/userfiles/file/xedegute.pdfIn PDF document text
    • http://gelikonline.ru/content/Files/71270481616.pdfIn PDF document text
    • http://alkanboya.com/files/file///70137131301.pdfIn PDF document text
    • https://emons-verlag.com/testarea/cwsCMSlight/media/files/44691990343.pdfIn PDF document text
    • http://gaongonmaiphuong.vn/webroot/img/files/73807698085.pdfIn PDF document text
    • https://webkapper.nl/ckfinder/userfiles/files/mezutab.pdfIn PDF document text
    • http://giteduguedesboires.com/userfiles/file/13844630091.pdfIn PDF document text
    • http://icaalliance.org/filespath/files/20210903113856.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_off0000d025.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD025 9980 bytes
SHA-256: eead6e152acdc3510b9f81f9ff04d7750e531691ae6af4cb7972b77661eeb000
font_01_sfnt_off0000e627.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE627 18248 bytes
SHA-256: 848ed32e6f55b29f184540dc19e59a9832f80be66d3b5eba665e833020237196
font_02_sfnt_off0001141e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1141E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1