Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8ccbe7a4658db35…

MALICIOUS

PDF

96.4 KB Created: 2021-09-03 21:25:20 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: f3153ba29a4ed1dac9df408ae26ce803 SHA-1: 89e2a7ea70263af33f297ed24264f3a494c60621 SHA-256: c8ccbe7a4658db358c35e7a3fd76449b6eaef3f9b34067eb29168c6be4d26f0f
124 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ClamAV, indicating it likely exploits PDF vulnerabilities or contains malicious content. Heuristics reveal it functions as a link farm, directing users to numerous external PDF files hosted on various domains, some of which appear to be compromised CMS uploads. This suggests a phishing or malware distribution scheme, where the embedded links are intended to lure victims to malicious content.

Machine Learning

  • Nyx PDF Classifier suspicious score 0.2801

Heuristics 5

  • 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
  • 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://wastran.ru/uplcv?utm_term=redox+reaction+ncert+textbook+pdf PDF link annotation
    • https://vandolderskb.com/images/usr/17251352451.pdfIn PDF document text
    • http://cassotech.nl/site/data/ws/files/71550410067.pdfIn PDF document text
    • https://elitestrategyglobal.com/wp-content/plugins/super-forms/uploads/php/files/c07c84aee4c7b2c7c8041d49ad311cd0/76752861920.pdfIn PDF document text
    • http://music-summer-courses.eu/upload/files/62932147307.pdfIn PDF document text
    • http://citra.cl/userfiles/file/59647505981.pdfIn PDF document text
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a934ea6b776---68014130531.pdfIn PDF document text
    • https://www.inter-tube.co.uk/wp-content/plugins/super-forms/uploads/php/files/1e06a2acf34ac6ada6903ebfb73a4a21/84540431115.pdfIn PDF document text
    • http://bi-acaovo.com/upload/files/23409692576.pdfIn PDF document text
    • https://chungcungoaigiao.net/uploads/files/75151832407.pdfIn PDF document text
    • https://premium-house.uz/images/file/44898671415.pdfIn PDF document text
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae9b0961029---rorunazorabizonet.pdfIn PDF document text
    • http://penzionnakrizankach.cz/ckfinder/userfiles/files/zuwimoxofelizu.pdfIn PDF document text
    • http://www.pantonerestauri.com/ckfinder/userfiles/files/41977455500.pdfIn PDF document text
    • https://thealloywheelcentre.co.uk/wp-content/plugins/super-forms/uploads/php/files/451cd8d02f5bf2ba8ba361283bd17965/99355978370.pdfIn PDF document text
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/40b8eda943aa27a7814368c024833c41/noketobo.pdfIn PDF document text
    • http://globalroomplus.com/bot/ckfinder/uf/files/42352785179.pdfIn PDF document text
    • http://nawooelcs.com/upload/userfiles/2021/08/files/210809104204.pdfIn PDF document text
    • http://fortlauderdalelimorental.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607de1b79d7fc---xorano.pdfIn PDF document text
    • http://ppfi-online.com/userfiles/file/lufipinitubilapitaxafuvi.pdfIn PDF document text
    • https://bf-pomosch.ru/wp-content/plugins/super-forms/uploads/php/files/uf9dovpbqvabmea3m2q8fvk0n0/luxomojaxeninosekizabi.pdfIn PDF document text
    • https://marblo.ph/app/webroot/img/files/49699337583.pdfIn PDF document text
    • http://aquarium-kochi.com/app/webroot/ckfinder/userfiles/files/roxibarumuxabaxojumotesu.pdfIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000120bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120BF 10776 bytes
SHA-256: a4a4869da75568579f396914caded53e7dee84f51613331c5270a364ef86795e
font_01_sfnt_off00013974.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13974 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00015186.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15186 19012 bytes
SHA-256: 6c0d32687d53514174d0b923d73cafcb2c60ccc1362a75cfcc0f0ebc53d667a6