Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6efd3bef3ecd454…

MALICIOUS

PDF

89.0 KB Created: 2021-07-03 04:33:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 07253e0c9f5a774818f680a728c01137 SHA-1: 6e3cc4da58bc4c9e2b5dd270b3f1826811eeae5b SHA-256: a6efd3bef3ecd454bddd36e51559927786b3e1627706928eb1a940be0b65b14d
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, indicating a high likelihood of malicious intent. It contains numerous external URLs, many pointing to compromised WordPress sites, suggesting it functions as a link farm or phishing lure. The presence of embedded URLs and the nature of the heuristics indicate that the primary goal is to redirect users to potentially malicious external content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://oniceh.ru/uplcv?utm_term=thesis+for+catcher+in+the+rye
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/160cc96639cd59---kewut.pdf
    • https://www.simplythebestevents.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608a199480814---wejemavuzusomefiditosuf.pdf
    • http://bluekeydigital.com/images/pic/file/298989828.pdf
    • http://jshtextile.com/UserFiles/file///37345405701.pdf
    • http://arebiatours.com/uploads/files/41008214075.pdf
    • https://izharfoster.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2021bf13c6---15500325701.pdf
    • https://rfcorporation.net/wp-content/plugins/super-forms/uploads/php/files/6c79da88cd3ac5ec400b3765d25c3d55/95601010859.pdf
    • https://beaumont-residence.com/wp-content/plugins/super-forms/uploads/php/files/vjp5ct3p3s8esbs4dp3ve9tj53/22353786102.pdf
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/160790873608e8---62686991698.pdf
    • http://csc-0898.com/userfiles/file/20210607033023_7tpc8s.pdf
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160846ee0925b8---nekujopumopiwutelafa.pdf
    • http://www.mtpartnersfl.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fc07ca5f9c---jewilirakekutax.pdf
    • https://ambalatender.com/upload/files/mozozopa.pdf
    • http://www.aadhar-interior.com/userfiles/file/bodibekavonesazukog.pdf
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16076370a6aa0d---fajomexumetukurijos.pdf
    • http://ventilyatsia-v-sochi.ru/ckfinder/userfiles/files/tuwofor.pdf
    • http://akgikorea.com/file_upload/fck_upfile/file/wuxex.pdf
    • https://transcendenceit.com/wp-content/plugins/super-forms/uploads/php/files/91770fc0ba8a7cdf9d05c1debb68dd10/pirodasuze.pdf
    • http://naturallabs.fr/userfiles/file/zonobebisomufowu.pdf
    • http://juniorsmagazine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608843367cd8c---15539342702.pdf
    • http://bellina.pl/userfiles/file/xanigufopo.pdf
    • https://esprimagroup.com/userfiles/file/vakosonolilosiponep.pdf
    • https://xn----7sbabak5acz7byau.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/27010ba4bc1999b998b901c87bbf2264/51336384850.pdf
    • https://archltginc.com/wp-content/plugins/super-forms/uploads/php/files/db94025a93e5db207c0c8a56ba4f1812/47478990196.pdf
    • http://niengrangchuyensau.com/upload/contentFile/file/tumanazofefapelosawib.pdf
    • http://www.timtransportes.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160bd04e419537---73070670120.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_off0000fa15.bin
d2da3dec502957d1b6ba8fa50cb4ef68e76fe88bc2802cc33cd1055e830ce00f
pdf-font-stream PDF embedded font (sfnt) at offset 0xFA15 17020 bytes
font_01_sfnt_off0001269c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1269C 16792 bytes
font_02_sfnt_off00013eb3.bin
1397b5644524ba40c4604c99be5b553e2a1163a9178aeb34eac36fec6250477d
pdf-font-stream PDF embedded font (sfnt) at offset 0x13EB3 10464 bytes