Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b0237f1b87f5743…

MALICIOUS

PDF

82.3 KB Created: 2021-08-29 14:09:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: d78f148337a5d8beb76e85db2f422682 SHA-1: 13c02b214153263f4f2a61ecb1563cff33724065 SHA-256: 8b0237f1b87f5743b3ffc1d7c485037709eb6ea1e325ac6c17e48f50d106ccb1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of links, many pointing to compromised CMS uploads and disposable hosting, indicating a link farm for SEO manipulation or to distribute further payloads. ClamAV detected this as Pdf.Phishing.Trojan, and an ML classifier also flagged it as malicious. The file's structure and numerous external links suggest it is designed to lure users to potentially malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://ctyrkolky-gamax.cz/data/dokumenty/87278926600.pdf
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/16116b13331b4c---81215374002.pdf
    • http://fslawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/7596456298.pdf
    • http://dodici12.ru/wp-content/plugins/super-forms/uploads/php/files/5kvjo6adkjeq7e9oc7smuiq7l5/koseniwud.pdf
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160fd9fba5cc17---46848507215.pdf
    • http://hopkinshigh1961.com/clients/878968/File/14884676968.pdf
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/160940f5972f17---46452275045.pdf
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a45b9a6fdcf---63972431515.pdf
    • https://presstone.hu/userfiles/file/babonovepelavefo.pdf
    • http://jedwines.com/cmsCart//upload/file/zupevezegelenosodelu.pdf
    • http://mwflower.com/upimagesfile///pigisur.pdf
    • https://hargagila.com/uploads/image/files/jetununafawa.pdf
    • http://laarakkers.com/ckfinder/userfiles/files/tometanotilomogisabimo.pdf
    • http://forglass.sk/userfiles/file/80904883723.pdf
    • https://hacunamatata.ru/wp-content/plugins/super-forms/uploads/php/files/6088a288db7e20adbd1317b9843201f1/somuxuxoloruzagabifupuseb.pdf
    • http://marinda.ru/pics/images/file/84497827758.pdf
    • https://www.vedaaz.com/wp-content/plugins/super-forms/uploads/php/files/9d613228267ca1c1be8d67b313c80ab0/patepifufawejop.pdf
    • http://www.ez4parcel.net/upfile/files/2021/08/19/gigunujisoradibopedekiros.pdf
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/16086488299440---vasaletukiwamagafilo.pdf
    • https://bloomeng.com/uploads/81952980415.pdf
    • https://ncfouting.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a654327429f---6848853727.pdf
    • http://famillespourstarlight.ca/clients/a/a9/a9b42c05011d3bb27e7f7ec2ed30324f/File/47130973610.pdf
    • http://thucphamchucnangmy.vn/uploads/files/44686315308.pdf
    • http://ylgems.com/file_media/file_image/file/selatatozezetozapodun.pdf
    • https://nonbodepsg.com/uploads/files/81863476233.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=how+to+take+golden+hour+photos
    • 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_off0000df27.bin
6825bf893c221fde2b42f4cdad0508844dec2bf586f01d1e2ff41800086444bd
pdf-font-stream PDF embedded font (sfnt) at offset 0xDF27 10848 bytes
font_01_sfnt_off0000f7fc.bin
672607ad990990f8ff118904217d3d3c69d6187670e9a28bdccbfed9e8e337f0
pdf-font-stream PDF embedded font (sfnt) at offset 0xF7FC 17132 bytes
font_02_sfnt_off00012391.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12391 16792 bytes