Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa07635df8b0af25…

MALICIOUS

PDF

74.2 KB Created: 2021-09-13 07:49:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 4daa8aea4c51796104ee7679c4c36f79 SHA-1: 800866129239988183af9bebe534c45fe550cb68 SHA-256: aa07635df8b0af25f83182a811df0557bb58eb48d5e04319f0da810794292919
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous embedded URLs pointing to external PDF files hosted on various domains, suggesting a link farm or redirection mechanism. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a large number of links on disposable hosting. While no scripts were explicitly extracted, the nature of the embedded URLs and the detection suggests a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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 http://elateridae.com/images/FCKeditor/file/93084396543.pdf In PDF document text
    • https://synodradomski.pl/userfiles/file/nagipimofarokigugivojus.pdfIn PDF document text
    • http://gerastar.com/userfiles/file/tixefinutovusixovodufe.pdfIn PDF document text
    • http://klccpa.com/userfiles/file/vuzasilibatomevozire.pdfIn PDF document text
    • http://dh-cell.net/ckfinder/userfiles/files/68769728086.pdfIn PDF document text
    • http://mestav.sk/uploaded_images/file/dumevasakipatakifaj.pdfIn PDF document text
    • http://hillcrestneighborhoods.com/userimages/bavexevujefuripuwoda.pdfIn PDF document text
    • http://terwaarde.be/ckfinder/userfiles/files/fajupe.pdfIn PDF document text
    • http://bmcnx.com/userfiles/file/97680067653.pdfIn PDF document text
    • http://delta-serwis.pl/pliki/fomolofuzawagidusuk.pdfIn PDF document text
    • http://kasaitogo.com/uploads/files/kozuluxubegojipafikawe.pdfIn PDF document text
    • http://www.videobezopasnost.ru/ckfinder/userfiles/files/xudugesa.pdfIn PDF document text
    • http://www.andreapondika.cz/file/77919666656.pdfIn PDF document text
    • http://apnschool.in/singhania/downloads/file/41176332247.pdfIn PDF document text
    • http://inhome360.ru/admin/ckfinder/userfiles/files/48593904233.pdfIn PDF document text
    • https://rosebankprimary.co.za/inc/ckfinder/userfiles/files/luweg.pdfIn PDF document text
    • http://bolt-go77.com/fckeditor/userfiles/file/jeduzozoturug.pdfIn PDF document text
    • https://baust.edu.bd/app/webroot/ckfinder/userfiles/files/77215089664.pdfIn PDF document text
    • http://vektor-bezpeki.com/userfiles/files/19146706262.pdfIn PDF document text
    • http://pcserviszlin.cz/ckfinder/userfiles/files/tixovexusag.pdfIn PDF document text
    • http://csc0851.com/userfiles/file/20210901125741_97vm3g.pdfIn PDF document text
    • http://studiogeologicotrilobite.com/userfiles/files/lazetajol.pdfIn PDF document text
    • http://open.ua/uploads/ckeditor/files/88215440811.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=friv+4+2018PDF link annotation
    • 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_off0000bc5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC5A 9892 bytes
SHA-256: 80116b33e0d23c30b3a678830c655f1a83951ba4ad56d526355337e5a6cc5b62
font_01_sfnt_off0000d250.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD250 18492 bytes
SHA-256: c1906ef66defae675d18b0f407d1e60e6d6843cb1888866f4d40093fea2ec563
font_02_sfnt_off00010286.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10286 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1