Malicious PDF — malware analysis report

Static analysis result for SHA-256 af44f4c8dd7848ff…

MALICIOUS

PDF

71.5 KB Created: 2021-10-04 09:20:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 2508b734db0df79600e355f95f1e55d5 SHA-1: ab86f81038c64f0cf02d27183a9603df1cb3f62a SHA-256: af44f4c8dd7848ffc009affa8f378ebf60bde4f7e6ca612e63353e630b3104e7
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ML classifiers and ClamAV, specifically identified as a phishing trojan. It contains numerous embedded URLs pointing to external domains, suggesting a link farm or redirection mechanism to deliver malicious content. The PDF structure and embedded URIs indicate it's likely used as a lure in a phishing campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://wastran.ru/uplcv?utm_term=find+the+median+of+the+data+24+36+46+17+18+25+35 PDF link annotation
    • https://ecoverservice.be/gallery/file/7193383225.pdfIn PDF document text
    • http://stefanourso.com/public/userfiles/file/26599368896.pdfIn PDF document text
    • http://kiko168.com/UploadFile/file/20210917013319596.pdfIn PDF document text
    • https://www.baust.edu.bd/app/webroot/ckfinder/userfiles/files/jamoburisirume.pdfIn PDF document text
    • https://gangnampools.com/contents/files/76314960588.pdfIn PDF document text
    • https://ksmt.edu.np/assets/ckfinder/userfiles/files/falexebadegaxok.pdfIn PDF document text
    • http://mtjjt.com/2013/upload/article/files/210930153015719945maofb.pdfIn PDF document text
    • http://npi-management.org/ressource/site-image/files/wubesofefajud.pdfIn PDF document text
    • http://burattinojatek.hu/userfiles/file/dowesopudokuxota.pdfIn PDF document text
    • http://studiotecnicoligioni.com/userfiles/files/13978899912.pdfIn PDF document text
    • http://delfosventures.net/userfiles/files/tanawuvekarizebigitem.pdfIn PDF document text
    • http://purofirstli.net/userfiles/file/tokonabiwusimojowogav.pdfIn PDF document text
    • https://tinhhoaxanh.vn/userfiles/file/zumabuwaboki.pdfIn PDF document text
    • http://xn----1-6cdapb2bdyqawnpcindqfc.xn--p1ai/media/file/63906680544.pdfIn PDF document text
    • https://dakotaterritorydevelopment.com/ckfinder/userfiles/files/82582548747.pdfIn PDF document text
    • http://phutunggiahungoto.com/uploads/files/goliruvuwedere.pdfIn PDF document text
    • https://marwaservicecenter.com/nbloom/fckuploads/file/83300948700.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/e1f5d78ccb7476caea78de2eefc52e27/68149316853.pdfIn PDF document text
    • http://105chers.netsociality.com/upload/files/gepobat.pdfIn PDF document text
    • http://conomiya.com/images/uploadedimages/file/86137645603.pdfIn PDF document text
    • https://mobilaide.com/upload/editor/file/xavojamogo.pdfIn PDF document text
    • https://eurosan.pl/user_images/file/28130862542.pdfIn PDF document text
    • https://www.avenueroadadvertising.com/wp-content/plugins/formcraft/file-upload/server/content/files/161475dc99cabb---siduzebizi.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_off0000b1f4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1F4 16524 bytes
SHA-256: c1024929cb726500b3f7bd0ad4a463615c885317e4f7810748eab08ff67cae17
font_01_sfnt_off0000db99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB99 11264 bytes
SHA-256: ebf6c1892909ada169299080ce414565bcc39f4d1a7684e3e694671b27f2e6d6
font_02_sfnt_off0000f600.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF600 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1