Malicious PDF — malware analysis report

Static analysis result for SHA-256 f7c1b826e6006042…

MALICIOUS

PDF

81.6 KB Created: 2021-09-07 22:50:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 3daa9651d9058304bea29e5328915de4 SHA-1: db642b91d8ad3ad14a4b00567288914bd944fc2e SHA-256: f7c1b826e60060420a1ee5e3344df57f54806663a5580df7022f47554a2707b1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous links to external websites, many hosted on compromised CMS platforms, suggesting a phishing or malware distribution scheme. The presence of PDF-specific heuristics like 'PDF_URI' and 'PDF_SEO_DISPOSABLE_LINK_FARM' further supports this, as these rules often trigger on documents designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://nomylo.ru/uplcv?utm_term=asme+boiler+and+pressure+vessel+code+pdf+2019 PDF link annotation
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160735fef8476b---xizolekinogiwatobiwa.pdfIn PDF document text
    • http://kcde.kr/userfiles/file/19731974276.pdfIn PDF document text
    • https://www.ezhealthcheck.com/wp-content/plugins/super-forms/uploads/php/files/fjd3iijqnunh8veur7ermjm7qj/saduf.pdfIn PDF document text
    • https://dtcprojects.com.au/wp-content/plugins/super-forms/uploads/php/files/kb77o1ij24ier13jk7q5us59a8/bugoloperokevogijeviritu.pdfIn PDF document text
    • http://narcisse.sk/editor_uploads/files/1489120302.pdfIn PDF document text
    • https://kvkumariajnkvv.org/singhania/downloads/file/34274473026.pdfIn PDF document text
    • http://aias.pnu.ac.th/ckfinder/userfiles/files/vagawivelarebag.pdfIn PDF document text
    • http://stamforgtechnologies.com/uploads/53281822826.pdfIn PDF document text
    • https://ita.kru.ac.th/ckfinder/userfiles/files/zeravob.pdfIn PDF document text
    • http://themultifold.com/wp-content/plugins/super-forms/uploads/php/files/4ne0c1q8dglsfao8o350hdh9t0/82554587822.pdfIn PDF document text
    • https://iqmuseum.mn/uploads/files/vesepafunaj.pdfIn PDF document text
    • http://m2m2design.com/userfiles/24807259457.pdfIn PDF document text
    • http://studiolaviano.it/userfiles/files/28023260677.pdfIn PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/160b0f63b3c8ee---38836255410.pdfIn PDF document text
    • http://www.siposferenc.hu/html/fejok.pdfIn PDF document text
    • https://sanvexe.vn/webroot/img/files/53294959291.pdfIn PDF document text
    • https://thejasmineway.net/wp-content/plugins/super-forms/uploads/php/files/fcteej8c49t7clhs7bijvittv4/20726670471.pdfIn PDF document text
    • http://zrdb-drogbud.pl/Upload/file/434089402.pdfIn PDF document text
    • http://kielcenoca.pl/files/file/51785528624.pdfIn PDF document text
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/9ivo6nbhtrgo8defa03501mruo/ditana.pdfIn PDF document text
    • https://livingcircles.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160a3c4513e6a4---wosowevumajenemu.pdfIn PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9ba1cc2f3e---tafuj.pdfIn PDF document text
    • http://bscartridge.com/pic/62800410608.pdfIn PDF document text
    • http://womenscouncildallasarboretum.org/clients/85748/File/mijutelubunupazepu.pdfIn PDF document text
    • https://hotel-la-licorne.fr/userfiles/file/39397292894.pdfIn PDF document text
    • 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_off0000d7a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7A0 11432 bytes
SHA-256: 7621dc682f5c3526abc677ab47245027e4bdd82b556ef71da9281731b38955e8
font_01_sfnt_off0000f275.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF275 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010a87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A87 17636 bytes
SHA-256: 1a0d159b5d3ad41ae664282888b9b86d17216feddbd9c616c9193a60e47ff045