Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6310b854cf1ebbe…

MALICIOUS

PDF

68.9 KB Created: 2021-09-25 00:45:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: eff0a46cf54b7b31388d6877333ae9ee SHA-1: 7e1ac37bacc238f77a415ee4a5b02e61de4c1c4a SHA-256: a6310b854cf1ebbe4d0fb196a14ab803f231f78395c5b17c4018014acaf2a55d
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 heuristic PDF_SEO_DISPOSABLE_LINK_FARM further supports this, indicating a strategy to distribute content via numerous disposable hosts.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://cleangroupbd.com/ck/upload/files/37681745077.pdf In PDF document text
    • http://verzorgingsindex.nl/images/uploads/99611473017.pdfIn PDF document text
    • http://athaj2.specialty-match.com/upload/files/32464094070.pdfIn PDF document text
    • http://unsersohn.ch/images/file/gexotulawolusituramugi.pdfIn PDF document text
    • http://alconsprom.ru/ckfinder/userfiles/files/bofuv.pdfIn PDF document text
    • http://softtox.pl/new/userfiles/file/3564962008.pdfIn PDF document text
    • http://darangyi.com/userData/board/file/68271414213.pdfIn PDF document text
    • https://enerjimakine.com/tsrm1/img/userfiles/file/97255371056.pdfIn PDF document text
    • http://consol.hu/images/uploadedimages/file/462570809.pdfIn PDF document text
    • http://xn--80aamwn.xn--p1ai/userfiles/file/52778847330.pdfIn PDF document text
    • https://gamma-electronics-eg.com/userfiles/files/tobuzudebafidatovu.pdfIn PDF document text
    • http://zbirozskepodzamci.cz/userfiles/3717750711.pdfIn PDF document text
    • http://xn--b1akwe.xn--p1ai/userfiles/file/besokutoxonerubeva.pdfIn PDF document text
    • http://think6.net/ckfinder/userfiles/files/20210925052927.pdfIn PDF document text
    • https://icon-studios.com/userfiles/file/40829526644.pdfIn PDF document text
    • https://braveathlete.net/geektic/files/fotozojada.pdfIn PDF document text
    • http://sugarfree-gelato.com/upload/file/paxufiseguwabirelafuj.pdfIn PDF document text
    • https://506hlapeta.com/files/file/20387591191.pdfIn PDF document text
    • http://cesishotel.com/res/wysiwyg/file/28098578339.pdfIn PDF document text
    • http://dichvugiayphep.biz/upload/ck/files/forisodubazoparujunibuv.pdfIn PDF document text
    • https://xn--80aaijz0c.xn--p1ai/ckfinder/userfiles/files/59107210843.pdfIn PDF document text
    • http://cgpharma.in/cote_dor_import/admin/ckfinder/userfiles/files/20961130383.pdfIn PDF document text
    • http://chinalabware.ru/d/files/8386065795.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=dragon+ball+z+episode+206PDF 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_off0000acb1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xACB1 11080 bytes
SHA-256: fc3612e94281757489754d3f7ed5eb5dcc83e7b380ba68dd2f1a219b076ec663
font_01_sfnt_off0000c632.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC632 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000de44.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE44 15268 bytes
SHA-256: 1e718a7fdc5fe4a9ad8727e1c2cd333e975ec32900cd6a5bb7e7cb370820a813