Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8512a2afa9688ab…

MALICIOUS

PDF

79.6 KB Created: 2021-08-28 23:43:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7bd430f8288354cc740c7ff5b8764c70 SHA-1: d18fb007b4c5f90c1ba5b2adcd651b40a9956825 SHA-256: c8512a2afa9688ab18ae2878735534e9b569e98266198c11b10bba0670f773e4
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 and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous links, many pointing to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The document body is heavily obfuscated and unreadable, indicating an attempt to hide its true purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9929

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 https://on-call-anatomist.org/ckfinder/userfiles/files/90224748241.pdf
    • http://charivne.info/images/file/gopereralogizaderuwuviko.pdf
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609619cd13b66---petavenopezo.pdf
    • http://sieckultury.pl/wp-content/plugins/super-forms/uploads/php/files/6ec5e753d0ad8f93b6faf50788e3bcf3/megoji.pdf
    • https://afra24.com/basefile/afra24/files/99130225778.pdf
    • http://bennett-legal.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/88345762137.pdf
    • http://logisticsnetworks.net/ckfinder/userfiles/files/557046238.pdf
    • https://enville.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078528f2da01---kevujuxuzitasubogi.pdf
    • http://giasuthienphuc.com/Images_upload/files/24119391596.pdf
    • http://hyunbulsa.org/~ewedd2/userfiles/file/musasobutezigiwusuvog.pdf
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6ca42e1eb5---gotogumemajofetugirup.pdf
    • http://clinicaveterinariacene.com/userfiles/files/xusijorusoriwabuwav.pdf
    • http://thedreams.cz/files/lirojotisuda.pdf
    • http://pantryscan.com/123cars/imagefck/file/lejomu.pdf
    • http://www.hotel-margherita.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609429915f222---jovarojudolopere.pdf
    • http://e-sportis.com/images/upload/5318769964.pdf
    • https://hijaustabilo.com/contents/files/39669059024.pdf
    • http://shijijiaming.net/filespath/files/20210819121648.pdf
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c70666bd1bd---42220101479.pdf
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/160bd22530e46c---39592842761.pdf
    • http://wellfoto.cz/pictures/files/nusigisupefil.pdf
    • http://afghansolar.com/userfiles/file/31477331122.pdf
    • https://www.citysecurity.org.uk/wp-content/plugins/super-forms/uploads/php/files/g3dlocl771esbdb2k9q5f2mfk0/xexupepir.pdf
    • http://perfectionistpaintingnj.com/ckfinder/userfiles/files/30877777888.pdf
    • http://nurugelexport.com/ckfinder/userfiles/files/6175322970.pdf
    • http://studiosiciliani.eu/userfiles/files/65574638819.pdf
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/160da52f0bd41e---80829511546.pdf
    • http://ri-rm.ru/userfiles/file/finotupom.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=8+business+days+from+today
    • 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_off0000d596.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD596 16792 bytes
font_01_sfnt_off0000eda8.bin
6c37c162e530d7a5e8239a023583f15173966057927cd71866e6a26ae04a6cd5
pdf-font-stream PDF embedded font (sfnt) at offset 0xEDA8 16056 bytes
font_02_sfnt_off000116d2.bin
4d7aa7efa2f2074e2d870a69f73a9a92f6cf392adac21d2b467a896526c25e72
pdf-font-stream PDF embedded font (sfnt) at offset 0x116D2 10932 bytes