Malicious PDF — malware analysis report

Static analysis result for SHA-256 4b21469eabb6d8ec…

MALICIOUS

PDF

89.4 KB Created: 2021-09-22 10:16:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ec64f190d50064517e031fa5c6c8c8ab SHA-1: 09f9a41718c0637b61cae5f76ac908a1293f382e SHA-256: 4b21469eabb6d8ec16bbd003b0e75fa699918f62fa80815294fc787d4d113eaf
154 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics suggest it functions as a link farm and employs callback phishing or tech-support scam lures, aiming to trick users into downloading further content. The presence of numerous unknown URLs associated with file hosting reinforces this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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
  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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 http://cuanhuaabshanquoc.vn/files/51147663231.pdf
    • http://nwatchonline.com/userfiles/file/wigosobidavujez.pdf
    • https://ecohort.info/userfiles/files/82437112604.pdf
    • http://innersolutions-uk.com/file/zufozo.pdf
    • http://srihemkuntschoolint.com/slbdavbatala/userfiles/file/vujoza.pdf
    • http://yalcinsezer.com/upload/ckfinder/files/dereve.pdf
    • https://selapro.com.au/application/third_party/ckfinder/userfiles/files/bekadunusuninegoradaf.pdf
    • http://yishiweb.com/upfiles/files/20210901_090619.pdf
    • https://dodomacnosti.net/data/file/82481932661.pdf
    • http://kimwendelldesign.com/ckfinder/userfiles/files/jexasubabalajenekejal.pdf
    • http://panziofabian.hu/fck_kepek/39377426571.pdf
    • https://anakaygame.net/calisma2/files/uploads/8481852762.pdf
    • http://thegoshow.net/userfiles/file/64866423214.pdf
    • http://michelesherrinlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/70129611799.pdf
    • http://maha.tcnme.com/chop/multimedia/userfiles/file/65727582767.pdf
    • http://movitecnic.fr/ressource/site-image/files/44585841971.pdf
    • http://aliceinformaticasrl.com/user/pages/54453582954.pdf
    • https://coil.hk/upload/files/fejixovulojo.pdf
    • http://leeharringtonhomes.com/userfiles/file/xekevogefumifilavezadeb.pdf
    • http://jayeonrak.com/upfile_editor/2021/files/vefukaxav.pdf
    • https://weblative.com/wp-content/plugins/super-forms/uploads/php/files/muimu57hcjvrjmg2umd5l4aggd/pojiniwagotosax.pdf
    • http://parmalab.it/userfiles/files/vuzizaruso.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=install+xapk+firestick
    • https://mediaget.com/userfiles/files/jubafizotenepusudexefabi.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_off0000f32b.bin
a18d9c20049e6f2c4f4a20b31643ac4d714fecd2af9e938f33aedd1b294c5e7b		 pdf-font-stream PDF embedded font (sfnt) at offset 0xF32B 10500 bytes
font_01_sfnt_off00010b33.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1		 pdf-font-stream PDF embedded font (sfnt) at offset 0x10B33 16792 bytes
font_02_sfnt_off00012345.bin
0911b101e5aed3e3cb614a76a9d344bac037c521e316655f9e41d59ceec22a4d		 pdf-font-stream PDF embedded font (sfnt) at offset 0x12345 20320 bytes

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