Malicious PDF — malware analysis report

Static analysis result for SHA-256 e421f64d319b321c…

MALICIOUS

PDF

84.8 KB Created: 2021-09-10 02:32:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: a144019c7a8c728b63806ba5b318a489 SHA-1: e349f456b5cf8195ed5d0006ac8e91dc51e7074d SHA-256: e421f64d319b321ceb16ec08beaf59338fd2fecf08941fc6e9fa6c60cdd34385
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as a phishing trojan and ML classifier indicated maliciousness. It contains numerous embedded URLs, many pointing to potentially compromised websites or disposable hosting, characteristic of a link farm designed to redirect users. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this. No scripts were extracted, and the document body was unreadable binary data.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://tuzvedo.hu/elemek/file/91383696650.pdf In PDF document text
    • http://www.arborvitae.cz/ckfinder/userfiles/files/ratulubugej.pdfIn PDF document text
    • http://oris-am.com/editor_up/63530882495.pdfIn PDF document text
    • https://biorenta.lt/ckfinder/userfiles/files/17167487916.pdfIn PDF document text
    • http://yuseigachi.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16134e0d758d5a---94894711727.pdfIn PDF document text
    • http://xn--80aab8aioy.xn--p1ai/userfiles/file/35215934005.pdfIn PDF document text
    • https://giriconsultancy.com/content_files/files/gevibugisitilazejojope.pdfIn PDF document text
    • http://geodeslaboratori.eu/userfiles/files/ribebadetefenax.pdfIn PDF document text
    • http://bimbrlata.cz/UserFiles/File/mewuvugo.pdfIn PDF document text
    • http://nguyenphat.com/public/default/ckeditor/files/suputodipudajagegevin.pdfIn PDF document text
    • https://dp-engineers.com/admin/userfiles/file/lojizape.pdfIn PDF document text
    • http://s8radziejowice-paszkow.pl/userfiles/file/ladozo.pdfIn PDF document text
    • https://sunrise-photon.com/upfiles/editor/files/65307689831.pdfIn PDF document text
    • http://moveisgarciadigital.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16134f82c2d9b4---55077531112.pdfIn PDF document text
    • http://wwsm-hk.com/files/file/69092282001.pdfIn PDF document text
    • http://nirmalamathachurch.org/cms_uploads/image/file/davabam.pdfIn PDF document text
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a64a25e943---53188352432.pdfIn PDF document text
    • https://www.sesc-am.com.br/Selecao/ckfinder/files/98392053718.pdfIn PDF document text
    • https://realimpacto.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161332cbf1e21c---15624311854.pdfIn PDF document text
    • http://garderoba.sk/images/_file/92930435913.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/a2cab5d9b86b7b291a75b3c90e54dd96/49622524118.pdfIn PDF document text
    • http://kidneytracker.com/ckfinder/userfiles/files/77353582741.pdfIn PDF document text
    • http://uat2.hkha.com.hk/ckfinder/userfiles/files/70238829204.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=mobile+data+not+working+iphone+xrPDF 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_off0000e67a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE67A 17724 bytes
SHA-256: 9fe60976263ad138ca5ea791ea48ca62704424a935c6e10df4820bb47bd178d2
font_01_sfnt_off00011461.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11461 10916 bytes
SHA-256: 65d5219aaaac26dec0510b72469e3e9db93e92f79306655d59db21346acb8e09
font_02_sfnt_off00012d30.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D30 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1