Malicious PDF — malware analysis report

Static analysis result for SHA-256 121fb082288cd298…

MALICIOUS

PDF

80.1 KB Created: 2021-09-13 05:58:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 3b32e7738274a75eaa8fd05bca35a657 SHA-1: 650e1e7ace1946238b43533e9cdea15c7562d7c4 SHA-256: 121fb082288cd298ec3dd062babdcd71c9267f09265ca7a6c2e9a5c311ee0f7f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm with numerous URLs pointing to potentially compromised websites, as indicated by heuristics like PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. No scripts were extracted, but the structure and URL patterns are indicative of a malicious redirection scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://nasfthr.com/userfiles/file/bosoburoketusoxig.pdf In PDF document text
    • https://www.willmarshelter.com/ckfinder/userfiles/files/voleve.pdfIn PDF document text
    • http://telektrans.hu/editor_up/posarexususimasikig.pdfIn PDF document text
    • http://crystaltrade.hu/data/file/vagugupajuzavuwikan.pdfIn PDF document text
    • https://www.acta-mobilier.fr/ckfinder/userfiles/files/dotupobunegipanisom.pdfIn PDF document text
    • https://washlounge.in/ckfinder/userfiles/files/47273573935.pdfIn PDF document text
    • https://tessuno.com/upload/files/613ebcd1d7263.pdfIn PDF document text
    • https://www.displaysdirectaustralia.com.au/application/third_party/ckfinder/userfiles/files/nekajovenirerufanu.pdfIn PDF document text
    • http://giaexploring.it/userfiles/files/fibirajax.pdfIn PDF document text
    • http://glovimex.com/uploads/ckfinder/files/51929160330.pdfIn PDF document text
    • http://aranysolyomfeszke.hu/editor_up/70902066816.pdfIn PDF document text
    • http://www.advancedevents.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613dfe8bc09c8---tuviwuduguvog.pdfIn PDF document text
    • https://wct.goldcrownresort.com/magazine_files/files/25594273592.pdfIn PDF document text
    • http://www.beverburcht.nl/upload/files/96157570865.pdfIn PDF document text
    • http://www.heksan.com.pl/file/64060177846.pdfIn PDF document text
    • https://pristineleather.com/userfiles/file/fovibifijatesij.pdfIn PDF document text
    • http://gwardiajuvenia.pl/zdjecia/fck/file/kosuranugidudewazok.pdfIn PDF document text
    • http://jadeite.ru/images/file/53331303449.pdfIn PDF document text
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b18670c57f---32854801046.pdfIn PDF document text
    • https://adium.ru/userfiles/file/7577870922.pdfIn PDF document text
    • http://bogaarchitetti.it/userfiles/files/39438805987.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/161329ff5f3c60---nesapodaratobosir.pdfIn PDF document text
    • http://okmarin.ru/userfiles/file/22942575998.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=toefl+itp+practice+test+pdfPDF 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_off0000d4ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4CE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ece5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECE5 10472 bytes
SHA-256: e165ae3a86412d0a631f321485ddf4887f56b5e2cd749e07dc5f9031b07ae35c
font_02_sfnt_off000104cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104CD 17768 bytes
SHA-256: 7a7939f293b696ab73b5a914931369689acf8483c9caeafcea85f333cdbe8476