Malicious PDF — malware analysis report

Static analysis result for SHA-256 d9cec0cbb61756b3…

MALICIOUS

PDF

83.7 KB Created: 2021-09-17 11:04:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 749d6b99db34cb4a00b555b18bfe9d38 SHA-1: 6a6abc62e31b19275846dffc3a654eb0b98fc67b SHA-256: d9cec0cbb61756b3bb27c81825a95e5d9a3329eaa9adc832f6defbfbf949fa69
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised WordPress sites. The presence of embedded URLs and the nature of the heuristics strongly suggest an attempt to redirect users to malicious content, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://laborke.ru/uplcv?utm_term=increase+internal+storage+android PDF link annotation
    • http://bdsductri.com/upload/files/65939715932.pdfIn PDF document text
    • http://cistenivytahu.cz/upload/file/zibixuvuzusovabe.pdfIn PDF document text
    • http://schokofontaene.de/idata/kavupixumanikiritokigad.pdfIn PDF document text
    • https://strings97.hu/userfiles/file/zaguwudeguvapar.pdfIn PDF document text
    • https://digbijoynath.in/uploads/userfiles/files/64850426953.pdfIn PDF document text
    • http://2sisaccount.com/userfiles/files/49728980569.pdfIn PDF document text
    • https://digicpictures.com/downloads/tudezoruferuzigoxow.pdfIn PDF document text
    • https://doitoutdoorz.com/file/n7SAnuSPXM9b8OrI.pdfIn PDF document text
    • http://skybuildinfraprojects.com/uploads/3954691966.pdfIn PDF document text
    • http://notariocprietoa.com/notaria/documentos/files/71762420668.pdfIn PDF document text
    • https://sidexsideaudio.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614323c507c05---gezikibifajudewimili.pdfIn PDF document text
    • http://sydjpg.com/images/upload/file/20210907_020516_193.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/7s6qc9vlk5octf7u2it8aa9hmj/25593972577.pdfIn PDF document text
    • http://animalscipublisher.com/files/upfiles/file/12288577707.pdfIn PDF document text
    • http://ruizhishengwu.com/uploadfiles/file/111159597154.pdfIn PDF document text
    • https://vas-vill.hu/userfiles/file/76036855148.pdfIn PDF document text
    • https://joinvita.com/neu/userfiles/file/bebonozune.pdfIn PDF document text
    • http://www.lentilles-progressives.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16137e0f67683a---bekuxapijofujekebumerogo.pdfIn PDF document text
    • https://kingcom.edesign.fr/gr33/web/uploads/assets/file/34232539426.pdfIn PDF document text
    • http://taxplus.in/images/contentimages/files/52997326554.pdfIn PDF document text
    • http://atletika-pardubice.cz/files/file/wibisififetije.pdfIn PDF document text
    • http://nemdanangpho.com/uploads/2021-09-14/images/files/35712991359.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_off0000df3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF3D 19136 bytes
SHA-256: 5dc79e66ccdfaba218686036b87037d9c56c305037ecaabe86f599d218d3b5b2
font_01_sfnt_off00011160.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11160 10496 bytes
SHA-256: 0df573da0485462a51cd805d4acae5fee4d4e93bfc7af52e6aa19ab451d58292
font_02_sfnt_off0001291f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1291F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1