Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ef2fc6ec7cf733a…

MALICIOUS

PDF

74.3 KB Created: 2021-09-13 15:14:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 11d1d84c3a606284ec103c9adfdf1f21 SHA-1: 6b48fdbbdf7a9f45581e2d9da599c26524b6406b SHA-256: 8ef2fc6ec7cf733a0d07a6bb3de68bdc8a3a592f19f43b93fd9640f3f1cc3aee
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external PDF files hosted on various domains, with a high heuristic score for being a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. While no scripts were directly extracted, the structure and numerous external links suggest an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://bsinteriordesigner.com/userfiles/files/kerudeberu.pdf In PDF document text
    • http://gasthaus-steinkirchen.de/img/editor/file/lisixupulerom.pdfIn PDF document text
    • http://golfvillageonline.com/userfiles/file/25957752107.pdfIn PDF document text
    • http://henanshuangxin.com/d/files/26865960566.pdfIn PDF document text
    • http://leoclubmarsala.it/userfiles/files/jelugogimigemora.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161373916408b6---buxejinepu.pdfIn PDF document text
    • http://apluskleaning.com/admin/images/file/resuxapefonedob.pdfIn PDF document text
    • http://meble-tk.pl/userfiles/file/2922712764.pdfIn PDF document text
    • https://5of7edwardstreet.com/assets/media/files/87061611015.pdfIn PDF document text
    • http://rafaelstore.ru/upload/files/sapepadamoriwavafujorune.pdfIn PDF document text
    • https://ambulatorioveterinariosismondi.eu/file/66604030558.pdfIn PDF document text
    • https://safecampus.in/cmsCart/upload/file/datal.pdfIn PDF document text
    • http://aquaclub.hu/userfiles/file/wotagavepagekeretogofo.pdfIn PDF document text
    • http://www.de.ruben.pl/ckfinder/userfiles/files/mukep.pdfIn PDF document text
    • http://zaiger.ru/img/file/23203292804.pdfIn PDF document text
    • https://www.la-providence-ehpad.fr/ckfinder/userfiles/files/jagunivejuvegave.pdfIn PDF document text
    • http://www.opencalgary.org/wp-content/plugins/formcraft/file-upload/server/content/files/161316fb86b8d9---82785995633.pdfIn PDF document text
    • http://xn--12cfu9bc1efac9a9azfdsb7b9d1f0j.net/ckfinder/userfiles/files/ludemibevamusa.pdfIn PDF document text
    • http://dongphat.net/upload/files/1551101631.pdfIn PDF document text
    • http://rajhansnursery.com/userfiles/file/rubowakavunub.pdfIn PDF document text
    • http://yuanyoujie.vip/userfiles/file/12943780646.pdfIn PDF document text
    • http://logopeda-empatia.pl/content/file/kisujexapegil.pdfIn PDF document text
    • http://btsoft.vn/uploads/files/tujogobalu.pdfIn PDF document text
    • http://cnc-soustruzeni.cz/files/file/nefajagurobiworevevor.pdfIn PDF document text
    • http://joelcsimonesq.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/voborefoluke.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=lesbian+books+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_off0000c271.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC271 10436 bytes
SHA-256: c32f943a147f15a81674733fec09cc40437d7c333c50e2d5db236c28bb9edb54
font_01_sfnt_off0000d9f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9F8 16144 bytes
SHA-256: 2c5abcb76bc32f00e0b0217cc5b39a3a0d294cca0aa08a73c7c3ce719e68c3be
font_02_sfnt_off00010350.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10350 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1