Malicious PDF — malware analysis report

Static analysis result for SHA-256 a88164ef02916bcb…

MALICIOUS

PDF

93.6 KB Created: 2021-08-11 03:00:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: ab3d026650f29245189eb5ce7d1f35f5 SHA-1: cc15112220034f1142a164d70fc996a23dbf50a3 SHA-256: a88164ef02916bcb6e61d3435a69b810c2ab97777f926fe400297334097af5ba
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It contains a link farm pointing to various compromised CMS upload storage locations and disposable hosting, suggesting an attempt to distribute malicious content or phish users. The presence of numerous embedded URLs, many of which are unknown or point to potentially compromised sites, reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

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://celcg.pl/uploaded/file/kagumuxa.pdf In PDF document text
    • https://www.nosolodespedidas.es/wp-content/plugins/formcraft/file-upload/server/content/files/16071b58c73bf1---wujulidubive.pdfIn PDF document text
    • http://dahchen.tw/userfiles/files/2616900048.pdfIn PDF document text
    • https://akrmedia.no/ckfinder/userfiles/files/zaxosematukaderudi.pdfIn PDF document text
    • http://christopherdallo.com/file/jiwositubiv.pdfIn PDF document text
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/abc391c56406d8a98edb20ef4136d940/96771187992.pdfIn PDF document text
    • http://reutlinger.pl/userfiles/file/favuzivaniduduxugavuz.pdfIn PDF document text
    • https://darkoyunpin.com/calisma2/files/uploads/pelufafomumedunogumeviva.pdfIn PDF document text
    • https://csom.cz/wp-content/plugins/super-forms/uploads/php/files/74e151a0774a4227ac23692cc4f60f87/74353817761.pdfIn PDF document text
    • https://travels-ukraine.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a289196f67e---30234929818.pdfIn PDF document text
    • https://wentworthre.com/wp-content/plugins/super-forms/uploads/php/files/294875e5f83b8aa2a3b581f304e80a8c/jisapipikupujikoxetuk.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/160e7c45331318---62715325917.pdfIn PDF document text
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16095426bc065f---lidesiwizaxotabewewejime.pdfIn PDF document text
    • http://sharise.net/Uploadfiles/files/40059973594.pdfIn PDF document text
    • https://enville.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b009cbab640---lipujajosid.pdfIn PDF document text
    • https://idfusionllc.com/wp-content/plugins/super-forms/uploads/php/files/a752bacbdc5dd6955717b5aeb8c2c3ae/porasig.pdfIn PDF document text
    • http://volamtuyetthe.com/userfiles/file/67662405861.pdfIn PDF document text
    • http://nd-58.ru/wp-content/plugins/super-forms/uploads/php/files/4bdfad5402ca39b1d79e0374b87d88e8/kivare.pdfIn PDF document text
    • https://asiatravel.kg/wp-content/plugins/super-forms/uploads/php/files/4a781e9816960d760b73fd306a9865ba/fapoze.pdfIn PDF document text
    • http://hkwwta.org/userfiles/luxuki.pdfIn PDF document text
    • http://becro-plast.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16100e6f746f1d---tivorikewopa.pdfIn PDF document text
    • http://coutleelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/82634257535.pdfIn PDF document text
    • http://cementfeet.com/userfiles/file/47099745250.pdfIn PDF document text
    • http://xn----8sbxab3abskk3a2j.xn--p1ai/media/file/10140804454.pdfIn PDF document text
    • http://xiaohecollege.com/d/files/57347205169.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=exercice+calculer+une+dur%C3%A9e+cm1PDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f186.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF186 10536 bytes
SHA-256: c24027bedd61898cd70cfbe74e9e96d8be5b520a3484983280b0f09dad0e776a
font_01_sfnt_off00010920.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10920 16144 bytes
SHA-256: 7384f78f7eee0a7747af6aa54f6a012ae917b773c3daf511a94379393b43df11
font_02_sfnt_off00011ea9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11EA9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_03_sfnt_off000136bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x136BB 18512 bytes
SHA-256: 32dcfbf81b17fc355db2f0ec809e1da8af7c05b4f1606bc21a518b3f996d0fd1