Malicious PDF — malware analysis report

Static analysis result for SHA-256 88698a22898656fe…

MALICIOUS

PDF

81.3 KB Created: 2021-09-20 03:48:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c4b21612be97d90de1c32675228d1b45 SHA-1: 6c45f8d399a2733b4be967f1e8f8a8ced2e918ec SHA-256: 88698a22898656feb2b55a3a7cb5a40ece528c836eb43d514424cd64d5bb07e0
164 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to various external PDF files hosted on potentially compromised or disposable domains. The presence of a 'download button' lure further supports a phishing or social engineering attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://laborke.ru/uplcv?utm_term=idm+free+download+for+pc
    • https://people11people.com/uploads/File/rurinotuvazedilexuruwov.pdf
    • http://rowerowaszkola.pl/imgturysta/files/nenuvuko.pdf
    • https://ms01bet.net/contents/files/22206255104.pdf
    • http://mazdooradda.com/userfiles/file/89376600737.pdf
    • http://transporteslaplata.com/imagenes_web/file/97024094180.pdf
    • https://finestblogger.de/wp-content/plugins/super-forms/uploads/php/files/nur7p978cptnq2bt5uhbkbprtl/benetagasikimixaxativatut.pdf
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16137d272aea0d---83398200353.pdf
    • https://leuphuotcamap.com/uploads/image/files/viwixazununajole.pdf
    • http://emilymillerlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/tagotomavexoge.pdf
    • https://clinicscrm.com/img/files/96817965574.pdf
    • http://areaengineeringsrl.eu/userfiles/files/92864520114.pdf
    • https://xuanhongkhang.com/upload/files/99286456243.pdf
    • http://www.aceitunasdelguadalhorce.es/ckfinder/userfiles/files/57314848373.pdf
    • https://futurefacesmiami.com/uploads/file/3834929804.pdf
    • http://hurtowniagrafit.pl/userfiles/file/75174187974.pdf
    • http://nocleginaplus.pl/uploads/userfiles/files/lipelexusabumutepo.pdf
    • https://bistro-8.com/wp-content/plugins/super-forms/uploads/php/files/72a466b4be5d6c48500142a9f2271db6/64587008089.pdf
    • https://kebecelectrique.com/upload/editor/file/15670707649.pdf
    • http://xn--82cac8d3ajrc0gd0bo4a7nf3qg.com/userfiles/files/punefuvizoniniwibak.pdf
    • https://alistairmills.com/ckfinder/userfiles/files/vemupuxuxed.pdf
    • http://tkhomedeco.com/assets/uploads/ckedit/files/20210914111202.pdf
    • https://shidoremicrosys.com/media/rabegofilove.pdf
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130c7564e710---zimuziwizi.pdf
    • http://studiocinti.eu/userfiles/files/dezolinisobevijinuwuxe.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_off0000db16.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB16 16792 bytes
font_01_sfnt_off0000f328.bin
5469b0424253431b6dfd5f268772070e0e512962e3fe52d8fb54b20a8dbdf7fc
pdf-font-stream PDF embedded font (sfnt) at offset 0xF328 17092 bytes
font_02_sfnt_off00011fd9.bin
c18b2e60699f6d4fdf135ee6233e25397ca7b0f07c131ffb1444ed4836838606
pdf-font-stream PDF embedded font (sfnt) at offset 0x11FD9 10460 bytes