Malicious PDF — malware analysis report

Static analysis result for SHA-256 5837b0b531548040…

MALICIOUS

PDF

83.2 KB Created: 2021-09-19 07:05:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c813a3d23a29e5b05d67d69a4ce85309 SHA-1: c64205b67bc75636cda51ee981f9b86a3537e26f SHA-256: 5837b0b5315480407c6bb6232499ad4463575d559cce10d81db7169dcd9675cd
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links pointing to external resources, many of which are hosted on compromised WordPress sites or disposable domains, suggesting a link farm designed to redirect users to malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely to download a second-stage payload. No scripts were extracted, but the PDF structure itself facilitates the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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 https://projektovanje.info/userfiles/file/tetixapipe.pdf
    • https://andana.us/files/files/43316959540.pdf
    • https://pensiuneavalentina.ro/app/webroot/file/61001696138.pdf
    • http://www.oiseaubleu-promo.fr/userfiles/file/wuroxera.pdf
    • http://buydecor.ru/uploads/files/vefajasidutem.pdf
    • https://banderlogclub.ru/Files/file/bilamulozewedepunopo.pdf
    • http://israel-aliya.com/wp-content/plugins/super-forms/uploads/php/files/77170cecf02a8351dd265a7eb1394b2b/fumunomipebegalovidebo.pdf
    • https://cantellodetersiviprofessionali.it/uploads/file/80937881920.pdf
    • https://www.studiorosaliabusco.it/ckfinder/userfiles/files/vabadesisovov.pdf
    • http://degeninhotel.ru/admin/ckfinder/userfiles/files/memaperadogaxenilemix.pdf
    • http://ags-sib.ru/ckfinder/userfiles/files/97585584169.pdf
    • https://freshchannels.com/home/sites/freshchannels/public_html/ckfinder/userfiles/files/16357305893.pdf
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/3p8njqcbg71jh6los7o7m61tr3/31101056625.pdf
    • http://geraldinekilkelly.ie/43372498726.pdf
    • https://momentous-inst.com/uploads/image/files/pipafozosilusapasesetosuz.pdf
    • https://www.domosystem.gr/ckfinder/userfiles/files/kotilu.pdf
    • https://ourcampuswindow.com/ckfinder/userfiles/files/70612933693.pdf
    • http://conniecorsentino.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/11078634778.pdf
    • http://sakaryakasaplarodasi.org/userfiles/file/93831773724.pdf
    • https://b2bircruise.travflex.com/bot/ckfinder/uf/files/faxuv.pdf
    • http://ptk-astana.kz/wp-content/plugins/super-forms/uploads/php/files/2ed4c00c161a4565b81fcf4c13b11b96/kopexewojisaforikunipag.pdf
    • https://semangkabiji.com/contents/files/bomijunitarelupofutamajo.pdf
    • https://storycycle.com/ckfinder/userfiles/files/kibavaziwurun.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=minari+streaming+free
    • 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_off0000e104.bin
e73fdbeb6e5367ba63450aee3f7a0f716fff14e278c47ac6485cbe1bd40851de
pdf-font-stream PDF embedded font (sfnt) at offset 0xE104 17860 bytes
font_01_sfnt_off00010f95.bin
e32584e6980cbf102addca0f3c63d71703e94eee4770a176f16c73df30ed92a0
pdf-font-stream PDF embedded font (sfnt) at offset 0x10F95 10384 bytes
font_02_sfnt_off0001270e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1270E 16792 bytes