Malicious PDF — malware analysis report

Static analysis result for SHA-256 6ffb15f6bd1edbaa…

MALICIOUS

PDF

95.7 KB Created: 2021-09-01 21:22:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 16803e21aed415eb75da2260a4251f4d SHA-1: c87856a0f6ff57dab35da74c82a3cfe9550b901e SHA-256: 6ffb15f6bd1edbaa54ea2983bdf9bc4cba5712348eb652e0136d71aec3ca35cb
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm with numerous URLs pointing to other PDF files, many hosted on potentially compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the structure and URL patterns are consistent with malicious PDF lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://cbgnfinance.com/userfiles/file/ribexoxeboposudojuwove.pdf In PDF document text
    • http://technoculture.cz/admin/upload/file/63697387859.pdfIn PDF document text
    • http://esoftland.com/userfiles/file/14511643654.pdfIn PDF document text
    • http://strap.sk/uploads/file/29389446440.pdfIn PDF document text
    • http://lavalnerina.it/userfiles/file/xuluremudomaxunarefigav.pdfIn PDF document text
    • http://jaika.in/images/documents/files/59853724485.pdfIn PDF document text
    • http://brickform.cz/obrazky/files/busasorudatutunedutujon.pdfIn PDF document text
    • https://www.siemers-deutschmann.de/wp-content/plugins/super-forms/uploads/php/files/ulss3n835rs3cdqssgbflpb28e/lomegodinexaderumalili.pdfIn PDF document text
    • http://gtshotel.it/images/file/84927559239.pdfIn PDF document text
    • http://leaguengn.com/userfiles/file///97986626158.pdfIn PDF document text
    • https://www.lesson-online.org/wp-content/plugins/super-forms/uploads/php/files/c465rrgio8m37j2mjq4926o8o2/85052065115.pdfIn PDF document text
    • https://thic.muki001.com/plugin/ce1/ckfinder/userfiles/files/11374440672.pdfIn PDF document text
    • http://familiegravesen.dk/ckfinder/userfiles/files/28331237929.pdfIn PDF document text
    • http://tantusmarina.com/UserFiles/file/telanakagesi.pdfIn PDF document text
    • http://mariopresto.pl/userfiles/file/xelozikofowuja.pdfIn PDF document text
    • http://mdbim.pl/ubezpiecz/obrazy/file/vepuban.pdfIn PDF document text
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074d3a3a9884---11950222580.pdfIn PDF document text
    • http://anhbanglaw.com/userfiles/file/xivakejatarovuwe.pdfIn PDF document text
    • http://vom-ragnaroek.de/uploads/file/biwokamiwap.pdfIn PDF document text
    • http://cleannshieldflorida.com/wp-content/plugins/super-forms/uploads/php/files/8806445e42ce6d0297159ce3ae4d5ec9/62329674896.pdfIn PDF document text
    • https://markzone.az/wp-content/plugins/super-forms/uploads/php/files/bt5rk1vsmh2tg4kle290nddki7/8289845464.pdfIn PDF document text
    • http://meta-min.com/files/10440141747.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=baby+blue+ringed+octopusPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In 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_off00010e64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E64 11096 bytes
SHA-256: de71af4f7e18413e701bf6efcd936e7a5f7de1178920c1d6ab78852dc438e466
font_01_sfnt_off00012800.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12800 18484 bytes
SHA-256: d30a6cb3e5eee20197dad075a75c3bfbc98e324e79ec7c3e0a3646d8877d8275
font_02_sfnt_off0001583f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1583F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1