Malicious PDF — malware analysis report

Static analysis result for SHA-256 335144a1664e1ac4…

MALICIOUS

PDF

79.1 KB Created: 2021-06-28 22:48:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1af01c9a5cad84689f01b81fe3e14d3f SHA-1: df5de9d20b6559524210f1782614525a2b5a7bfb SHA-256: 335144a1664e1ac4fed25a8112b94a3354acdf8a2e68f571d7418174fee8ef12
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was detected as malicious by ClamAV and an ML classifier. It functions as a link farm, containing numerous embedded URLs that point to other PDFs hosted on compromised websites. The primary purpose appears to be directing users to malicious content, likely for phishing or further malware distribution. No scripts were extracted, but the PDF structure itself facilitates the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://spherule.org/wp-content/plugins/super-forms/uploads/php/files/9fb1000c393b4ced46b40c484b99c036/18337683787.pdf
    • https://a2designbg.com/userfiles/file/ruvubonosewagira.pdf
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160a1d0968498d---43442494906.pdf
    • http://camel-republic.com/media/userfiles/files/60767137394.pdf
    • https://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/0e449388aca62058774228d2e9cd0fd0/74119370318.pdf
    • https://pjkconstruction.ca/images/file/zexapitok.pdf
    • http://morethancars.nl/uploads/edytor/file/25798729442.pdf
    • http://nhatngungoisaoxanh.com/upload/files/72419005424.pdf
    • https://navliecky.net/userfiles/file/97501122334.pdf
    • https://noddy.nu/images/file/fobibazixujaso.pdf
    • http://www.gaviprintpack.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b006bccf91a---41347879548.pdf
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/dbh7tungckd2l3hljal8rsua12/51438154765.pdf
    • https://stagerightstaging.com/wp-content/plugins/super-forms/uploads/php/files/d32f3655171710f2f79add793f7866b0/kefoxobefabup.pdf
    • http://allg-gyn.ch/userfiles/file/rajutegedekulosad.pdf
    • https://purebodycare.courses/wp-content/plugins/super-forms/uploads/php/files/i55980n67ra571oh8sg5oemfs3/63761595316.pdf
    • http://xn--80ab1a9a.xn--p1ai/sadm_files/mosaredajuwisukefom.pdf
    • http://friluftsgruppen.se/wp-content/plugins/formcraft/file-upload/server/content/files/1609095896dca2---33799302513.pdf
    • https://heritagelogs.com/wp-content/plugins/super-forms/uploads/php/files/24sf3akjl8saht1cukjfuied10/naxorunajuvogopozir.pdf
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609b8cfc9b178---47081519767.pdf
    • https://www.chinacimctrailer.com/wp-content/plugins/super-forms/uploads/php/files/b66fb56f273033f46d52c77d035a466a/3524470081.pdf
    • https://www.idahomedia.com/wp-content/plugins/super-forms/uploads/php/files/d1bd27a873ac9959bc49dfb4c7837337/49174843682.pdf
    • https://www.mozartcantat.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607cf58fe5e3a---5397344320.pdf
    • http://brightwayconsultancyservices.com/userfiles/file/xanakado.pdf
    • https://www.frankcapassoandsons.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5ddd656f45---dalepajifivez.pdf
    • http://chagatea.ru/wp-content/plugins/super-forms/uploads/php/files/c2c89cff17901fd2e8bacc1d8ef6f6e1/silanazimumefadumopejamos.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=mobilitywod+positioning+posters+pdf
    • 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_off0000cdf6.bin
fabe958e559b0151d0681410b3211a6387514d44ef476d05d3863be96f9873ad
pdf-font-stream PDF embedded font (sfnt) at offset 0xCDF6 10844 bytes
font_01_sfnt_off0000e6c4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE6C4 16792 bytes
font_02_sfnt_off0000fed6.bin
52e0432134e5ab908ed5ce6b65af7aa9e6579e69c003b7c190f1156775e88d3b
pdf-font-stream PDF embedded font (sfnt) at offset 0xFED6 18280 bytes