Malicious PDF — malware analysis report

Static analysis result for SHA-256 5452b81cf26e317e…

MALICIOUS

PDF

87.9 KB Created: 2021-08-14 04:17:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 9c9464ea50df40c96c23f506425a70b1 SHA-1: 0c82a21f0e000ef2353bf5c19f42d4b35daefda0 SHA-256: 5452b81cf26e317e1d55eab35ffaf1670b48bb1bdb1df6d4766584e86dfc6f7c
156 Risk Score

Malware Insights

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

The PDF file contains numerous external URIs and links to various websites, many of which appear to be compromised or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and unreadable, providing no direct content clues, but the heuristic firings clearly point to a link farm strategy.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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
  • 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://philabc.ru/uplcv?utm_term=where+is+pioneer+woman+cookware+made PDF link annotation
    • https://digireg.cz/upload/30677086868.pdfIn PDF document text
    • http://emannsltd.com/userfiles/4016170798.pdfIn PDF document text
    • http://timebank.ru/sites/default/files/photos/pagefile/96668681391.pdfIn PDF document text
    • https://portsidestrategies.com/wp-content/plugins/super-forms/uploads/php/files/4134d186dace55cba0199583fda474fd/pibor.pdfIn PDF document text
    • https://ayurvedaemart.com/uploads/file/26048434989.pdfIn PDF document text
    • http://gorisum.net/fckeditor/upload_file/file/19373980209.pdfIn PDF document text
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c394178ff5c---binug.pdfIn PDF document text
    • http://shethof.ch/cgi-bin/dynamisch/file/92310266666.pdfIn PDF document text
    • http://cermak-expo.cz/data/files/file/wosikosapuzapa.pdfIn PDF document text
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160aa6a8800df9---44221902067.pdfIn PDF document text
    • https://www.lipfish.no/wp-content/plugins/formcraft/file-upload/server/content/files/16115b492b8b2b---8674968889.pdfIn PDF document text
    • http://tuclubcr.com/campannas/file/giwedufaf.pdfIn PDF document text
    • http://garderoba.sk/images/_file/624363329.pdfIn PDF document text
    • https://leesman.com/wp-content/plugins/super-forms/uploads/php/files/f92b13773b3f51e5cde80e49f524888d/27940809256.pdfIn PDF document text
    • http://jentretiens.ch/uploadimage/woxasekexiriwoxeteron.pdfIn PDF document text
    • https://futuresbuilder.net/dayafter/uploadimages/newsimages/file/mopadilisonorodazar.pdfIn PDF document text
    • http://branpc.in/ckfinder/userfiles/files/64583926272.pdfIn PDF document text
    • http://jts-electrical.co.uk/ckfinder/userfiles/files/sazatom.pdfIn PDF document text
    • https://andrejc.si/files/file/temodepegadepugibimo.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/160ecac8b16504---74225756084.pdfIn PDF document text
    • https://seeandhearbetter.ie/img/shop//contents/62827970460.pdfIn PDF document text
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ca1372ea3cb---8846684789.pdfIn PDF document text
    • https://epiphanych.com/images/file/welitijigewezujuz.pdfIn PDF document text
    • http://solarhomepage.ch/fckeditor/editor/images/file/rerefezugitofanasudojaxu.pdfIn PDF document text
    • https://kachhiproperties.com/wp-content/plugins/super-forms/uploads/php/files/lq17jsijvss89u0qth44ldbeb6/xoroluvabopoza.pdfIn PDF document text
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082f63c6d627---gakemiwazaliwokokojo.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_off0000f23e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF23E 10804 bytes
SHA-256: 20fd38e3cb5df817d626e6615ae7a271ee4603f91d1c77db50f3526993bf9e4b
font_01_sfnt_off00010b04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B04 17848 bytes
SHA-256: 1254aced829e08548eb34d2d6a7e00babf652fd4f39f0f4ed1a23808d3c882a1
font_02_sfnt_off000139d6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x139D6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1