Malicious PDF — malware analysis report

Static analysis result for SHA-256 31d81762a91606dc…

MALICIOUS

PDF

84.9 KB Created: 2021-07-01 17:41:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c8949b1db9f11a18f579982b92cad2ab SHA-1: 947ec706533b36399c8cb3e2c57f5b7a04dcb21b SHA-256: 31d81762a91606dc3ef56f87394d2ffffcb3e5d5e69b54f3cbab04d0e4e572dc
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with numerous URLs pointing to compromised WordPress sites. These links likely serve as redirects to malicious or phishing content, aiming to trick users into further compromise.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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 http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16077334b82408---49006408409.pdf
    • http://auburn-properties.com/userfiles/files/sizafuvanaxewawijikofezes.pdf
    • http://www.onekaddy.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bb1bebc64e9---vosuzojidifetu.pdf
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160888dfd9f1aa---bilasilabimiboxun.pdf
    • https://akapacha.com/userfiles/file/11026129162.pdf
    • http://www.adanakursmerkezi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f77f68befd---80016148113.pdf
    • https://weblative.com/wp-content/plugins/super-forms/uploads/php/files/f7f7r9fn35v63t7f89pgfsqv58/76564708729.pdf
    • https://totalyoumovement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609fc34f3890b---jaxiwof.pdf
    • http://www.fotografoeventimilano.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608eb2fbb7e33---jewolojudat.pdf
    • http://www.loicadesacavem.pt/wp-content/plugins/formcraft/file-upload/server/content/files/160841da61e9b2---riwunegipi.pdf
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160bdb2cb33200---94786861499.pdf
    • http://anhuishangbiao.com/upload_fck/file/2021-6-20/20210620074455888175.pdf
    • http://kaufdeinauto.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b5a4a8a55f3---gozapidivovupivade.pdf
    • http://evabody.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160c877a2cf20b---jitobidatabi.pdf
    • https://rfcorporation.net/wp-content/plugins/super-forms/uploads/php/files/ebe93f8b3f01796b65a94dd5fa172abf/nivoxabupatu.pdf
    • http://www.ddd-iasi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160965d4254a2c---bejimokegukaredibeku.pdf
    • https://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1607e65808089b---xalilupijamamogoruba.pdf
    • http://dailitara.lt/bites/uploads/file/96100308274.pdf
    • https://www.taxiserviceh24.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075abc8f1d78---93556643912.pdf
    • https://agrachoff.ru/wp-content/plugins/super-forms/uploads/php/files/0b09e84399df0f74d22e0eec3ff24840/ximoruzikexope.pdf
    • http://skrabl.pl/www/rpbd/fck/file/bozerisatobim.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=daily+free+coin+master+spins
    • 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_off0000e8b9.bin
23d59d8a86fe7ca5664b01d90ea2ea05676869055e7a7f405e34b611f7ab3b9a
pdf-font-stream PDF embedded font (sfnt) at offset 0xE8B9 10756 bytes
font_01_sfnt_off00010177.bin
f6056b6413edeb3f49dbd6a33808867c5d9a9bbed7a9e2681baf9a2f459d4fac
pdf-font-stream PDF embedded font (sfnt) at offset 0x10177 17368 bytes
font_02_sfnt_off00012e7a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12E7A 16792 bytes