Malicious PDF — malware analysis report

Static analysis result for SHA-256 57d4e9f139e15e73…

MALICIOUS

PDF

89.5 KB Created: 2021-07-04 07:08:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0b500f6809f16a1ea1f7dec260628c8a SHA-1: e2372488edade28dac011f8f2d936eba25b4fcd8 SHA-256: 57d4e9f139e15e73bb61be7b6f67790b15e9f16e09940520dc4e688ae084d083
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains numerous links, many pointing to compromised CMS upload directories and disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics strongly supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/84207fb8c936644c07360d563b9a89de/potabulovebizelogiki.pdf
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/bil41tqagquul9lfi0b66skgjs/linaruribabo.pdf
    • http://stasta.com/userfiles/file/21443224053.pdf
    • http://sts-logistika.ru/wp-content/plugins/super-forms/uploads/php/files/1fb86351eb8215067b0ae70c570ab560/natenes.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a2abb67bcc---90953899686.pdf
    • http://www.asejnrtigers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609b6af5a7f3a---50033318316.pdf
    • http://shukokai-voves.fr/userfiles/file/dedowezunezupozoposiluxum.pdf
    • http://www.alexgis.com/siteuploads/editorimg/file/27619179160.pdf
    • https://maturana.cl/upload/file/vuxibakag.pdf
    • http://www.armstrongre.com/files/files/48089527402.pdf
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/4ucvbkeussh2fsr9scnr32tmld/wumexojikajupumujoxefe.pdf
    • http://guitarenko.fr/img/files/jipisami.pdf
    • https://alixdemassy.fr/userfiles/file/15415586438.pdf
    • http://xn----7sbabaajmdfbk3ddf3azka3b6a2r.xn--p1ai/ckfinder/userfiles/files/70833776894.pdf
    • http://www.pointcookelectrician.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16075ac76de3d6---829741538.pdf
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/160987e5262a8c---47886926535.pdf
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/1609102e9020d7---78899235071.pdf
    • http://sazjah.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099c2839c430---12487551586.pdf
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160ba5283b8965---befebopanavikufuda.pdf
    • http://www.kliningstroy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160b137f0a55a5---kijoletipep.pdf
    • https://fontaine-eva.fr/userfiles/files/nudolemudosetem.pdf
    • http://aytekinpolatel.com/image/files/roxibazes.pdf
    • https://levin-dent.ru/wp-content/plugins/super-forms/uploads/php/files/4d3e72c0aa5882e5dd29066ac2b13b59/48694674507.pdf
    • https://www.guestquesttravelmedia.com/wp-content/plugins/super-forms/uploads/php/files/one4tq0albpbottnirvninsgsj/tajezera.pdf
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bcfda2e7230---63438265270.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/Om9ozkHLxGw/uplcv?utm_term=only+if+you+got+me+feeling+like+this
    • 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_off0000f8bf.bin
f311ec0d263ac4449c2da70bafaa22505cb83bb923f8eccca0b63efd68f6fe63
pdf-font-stream PDF embedded font (sfnt) at offset 0xF8BF 10728 bytes
font_01_sfnt_off00011140.bin
712f2f920a5b88e56a85fb6848b985116de672318b0ab979ac706c7603d20f5a
pdf-font-stream PDF embedded font (sfnt) at offset 0x11140 17456 bytes
font_02_sfnt_off00013ec2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13EC2 16792 bytes