Malicious PDF — malware analysis report

Static analysis result for SHA-256 53dcf3ee4d3e1a08…

MALICIOUS

PDF

74.8 KB Created: 2021-09-16 21:36:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 797abb0e23b5ba28f9e1ef42b90a9bb1 SHA-1: f082d5fdfa22b6e75b0d451cfe053cb3ab709b6d SHA-256: 53dcf3ee4d3e1a086549e8dc6e0392e24c06fcfcafe1d536e7c69391d2febee3
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains a large number of embedded URLs pointing to various domains, many of which appear to be disposable or link farms, suggesting a phishing or malware distribution campaign. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating the document is designed to host many links on potentially untrusted domains. No scripts were extracted, but the overall structure and URL distribution strongly suggest a malicious lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://chcial.ru/uplcv?utm_term=android+wifi+not+turning+on PDF link annotation
    • http://sergeisurzhin.ru/ckfinder/userfiles/files/sibarigaviferitin.pdfIn PDF document text
    • https://ubranni.com/uploader/files/58639982008.pdfIn PDF document text
    • https://greenways.at/userfiles/file/52565807946.pdfIn PDF document text
    • http://idcla.net/upload/files/newaforazevemigodemip.pdfIn PDF document text
    • https://www.loisirs-auto-occasion.fr/ckfinder/userfiles/files/sajimavidadilebusij.pdfIn PDF document text
    • http://peak-experience-europe.com/images/blog/file/91994976002.pdfIn PDF document text
    • https://www.hs-hofgastein.salzburg.at/ckfinder/userfiles/files/wijozuxatadozajobimuxeg.pdfIn PDF document text
    • https://hospvetcentral.pt/site/upload/file/38751413038.pdfIn PDF document text
    • http://baozhaopharma.com/upload/files/34893790933.pdfIn PDF document text
    • https://groupunsur1.com/contents/files/dusizexilefemitizewugikin.pdfIn PDF document text
    • http://360global.ca/userfiles/file/5936830525.pdfIn PDF document text
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/d7e1206fae4567a13fea51cae6b4c915/xamijikepaxebane.pdfIn PDF document text
    • http://www.roosprommenschenckelfoundation.nl/ckfinder/files/files/42503540204.pdfIn PDF document text
    • https://alice-immo.com/userfiles/file/32421272796.pdfIn PDF document text
    • http://flomojapan.com/upload/files/22653778528.pdfIn PDF document text
    • http://fabrykakonwersji.pl/wp-content/plugins/super-forms/uploads/php/files/946400d550e9a7a38d777eeee606034d/sogimavewarako.pdfIn PDF document text
    • https://izyskately.ru/foto/ck/files/3669399017.pdfIn PDF document text
    • http://www.egavilanes.com/ckfinder/userfiles/files/9993238570.pdfIn PDF document text
    • http://safeabortionnepal.com/userfiles/file/66339198914.pdfIn PDF document text
    • https://pmcp-avac.com/files/upload-ckfinder/files/wewidididigawa.pdfIn PDF document text
    • http://vstarmp.cn/upload/files/20210911_060359.pdfIn PDF document text
    • http://burmeseburmilla-allevamento.com/userfiles/files/gifixipivaz.pdfIn PDF document text
    • http://2m-m.eu/userfiles/files/96956822768.pdfIn PDF document text
    • http://2ds-creations.fr/userfiles/file/94232784414.pdfIn PDF document text
    • http://massimomoroni.it/userfiles/files/90987498786.pdfIn PDF document text
    • https://marblobaths.com/app/webroot/img/files/fipimokepaxofuvijipamaba.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_off0000c2ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2AE 17272 bytes
SHA-256: 89810a3b1a2de26adf5be2c897e79e58c6d43ac01c022213e2a6fdcf10e93cf2
font_01_sfnt_off0000eebc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEBC 10188 bytes
SHA-256: 0d9b1f686551ef69876419761b1152637b803119e528767355afc1e55008aee2
font_02_sfnt_off0001057d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1057D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1