Malicious PDF — malware analysis report

Static analysis result for SHA-256 4f9854f9f08b40fb…

MALICIOUS

PDF

82.2 KB Created: 2021-08-25 02:57:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b0bff1f653df3ee8cafbeefcb9f15092 SHA-1: 4e62e43244bd3905d5f7177706f38ae5440cddb9 SHA-256: 4f9854f9f08b40fbc563b0357bc92594999a220ca78e841edc90955cef626594
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF containing embedded JavaScript, which is a common technique for delivering malicious payloads or redirecting users to phishing sites. The presence of multiple URLs pointing to compromised WordPress upload directories and link farms suggests an attempt to obscure the final malicious destination. ClamAV detection and ML classification further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607985554bcd2---32380816742.pdf
    • http://oneself.pro/wp-content/plugins/formcraft/file-upload/server/content/files/1610a5631283c3---zevutedev.pdf
    • http://pogservice.ru/userfiles/file/39136299647.pdf
    • https://www.olympusnorge.no/wp-content/plugins/super-forms/uploads/php/files/0elgtod6mfpe38fc58dlp23a46/3728493151.pdf
    • https://inchirieriavioane.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160b1489142a90---rimadefinavegu.pdf
    • https://netlandschool.cl/files/80410820670.pdf
    • https://alfa-pechati.ru/wp-content/plugins/super-forms/uploads/php/files/74a72ebaf2e21f1080fa29321bc8ba18/52317154103.pdf
    • http://www.louisefarmersmith.com/admin/ckeditor/ckfinder/userfiles/files/rigavitag.pdf
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/1n58lrmkk028i3v059epvt93ki/46571719623.pdf
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd9ade08629---73152144304.pdf
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160775075d532b---72578443259.pdf
    • http://doo-san.com/userfiles/file/20210509023603.pdf
    • http://fitnessklub-impuls.pl/uploads/assets/file/pedexupigadozejezafisas.pdf
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/ec9e0987484bcab7e4cfad1e1f375bcb/nufelamibugibilijolulof.pdf
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160c0fa44d892a---judibevogufenukefakew.pdf
    • http://www.acefence.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608bd5ad58060---92758321350.pdf
    • https://goactive.hu/wp-content/plugins/super-forms/uploads/php/files/e7f13f27374312178f64e35e73c3b5d4/mepasujakezopejesume.pdf
    • https://marwaautorepair.com/nbloom/fckuploads/file/towubudigifogowu.pdf
    • http://topp.pl/_topp/file/lininu.pdf
    • http://saatgaamkansarasamaj.com/admin/uploads/files/33830882223.pdf
    • https://www.studioline.ie/ckfinder/userfiles/files/bipojazefenipiferetuju.pdf
    • http://ventiliatoriai.lt/js/ckfinder/userfiles/files/bakumap.pdf
    • http://wakingbeauty.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bbccc82f010---36524463822.pdf
    • http://clubcrudupsonoma.com/clients/1/14/14cf715f5cd05ddba197ceaa5938d7d5/File/53370188031.pdf
    • https://thriveelearning.com/wp-content/plugins/super-forms/uploads/php/files/09b01d4bd358850f26d687090890ca3d/79011358512.pdf
    • https://www.penyembuhanholistikreiki.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609405c75bcbf---17927405622.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=the+grill+works
    • 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_off0000e132.bin
84aa7ddd45980a06bc8d52747a9cf6d0aef76228e95f005a1a15ec3796418111
pdf-font-stream PDF embedded font (sfnt) at offset 0xE132 10164 bytes
font_01_sfnt_off0000f818.bin
6afe72ebb2ce2a2eccae87c3046d39e9d620bc5e26ad14c68fb66c9bff99255e
pdf-font-stream PDF embedded font (sfnt) at offset 0xF818 16684 bytes
font_02_sfnt_off0001236f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1236F 16792 bytes