Malicious PDF — malware analysis report

Static analysis result for SHA-256 277d18c67cc49d7a…

MALICIOUS

PDF

79.0 KB Created: 2021-09-12 19:51:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 71be0c79147eb07e61e38ed8ff58a192 SHA-1: faaaf9eba5509f4dfeb56ab97916dafd725a8d5f SHA-256: 277d18c67cc49d7a49d8025a67400a16e65afaf595e3e72f6580181a5a926f31
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was identified as malicious by ML classifiers and ClamAV. It contains numerous embedded URLs, many of which point to compromised websites or are structured as link farms. The presence of 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics indicates a pattern of using potentially malicious or compromised hosting for redirection. The primary attack pattern appears to be directing users to external sites, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://seto.cz/uploads/51538906164.pdf
    • http://caphegiabao.com/upload/fck/file/95366833674.pdf
    • https://vatlieutaphu.com/upload/files/94319377603.pdf
    • http://vaness-sens.fr/ckfinder/userfiles/files/1303726690.pdf
    • https://sunrise-photon.com/upfiles/editor/files/88047293399.pdf
    • https://belitour.ir/basefile/belitourir/files/rozumuvipapuvop.pdf
    • http://midospa.com/upload/files/witixobefutipuxefipaji.pdf
    • http://bacvietexpress.com/upload/userfiles/files/27101516079.pdf
    • http://www.naturapreserved.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135be49d843f---vilizevenipinijexobos.pdf
    • https://fertilizerproductionprocess.com/d/files/67596733038.pdf
    • http://abwlanham.com/uploads/files/55720536659.pdf
    • http://sutipatika.hu/userfiles/files/wuxasezirifulimaxe.pdf
    • https://asset-books.com/userfiles/file/32585434463.pdf
    • http://secretlove.ch/ckfinder/userfiles/files/69595227991.pdf
    • http://szjglaw.com/uploadfile/file/2021090221480773499.pdf
    • https://bistro-8.com/wp-content/plugins/super-forms/uploads/php/files/94a0e17ab06231ef59dab1d301ee4715/dabigafule.pdf
    • http://itemclinicchina.com/ckupload/files/wimowazexezufurov.pdf
    • http://lamgi.pl/ckfinder/userfiles/files/49722844965.pdf
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/347cbf6a7fd9981a735b306b8f10f9ab/53204391064.pdf
    • http://ledlight-lamp.com/mingyi/images/userfiles/file/pujuzekarewug.pdf
    • http://garant-fond.ru/ckeditor/ckfinder/userfiles/Images/files/mapuxatozase.pdf
    • http://platcometals.com/images/file/gevokoj.pdf
    • https://flylights.pl/wp-content/plugins/super-forms/uploads/php/files/cjp3a6r9higgkjju4275n3numn/murafenunodotepo.pdf
    • http://ampletrekking.com/userfiles/file/88147819948.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=james+and+the+giant+peach+full+story+book+pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cc46.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCC46 16792 bytes
font_01_sfnt_off0000e458.bin
5aa1deb37ea3b797886594e04e5fad44aff32f25f61a0205facd345afcf9bb96
pdf-font-stream PDF embedded font (sfnt) at offset 0xE458 18052 bytes
font_02_sfnt_off00011380.bin
e4dc39add0c41b402a5968672d279268629e085154206ced6ca5fffff197d6f0
pdf-font-stream PDF embedded font (sfnt) at offset 0x11380 11504 bytes