Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b686e1e40a6d87f…

MALICIOUS

PDF

85.4 KB Created: 2021-04-11 13:05:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 34b64c795f30cd6277745e39bb49d8d7 SHA-1: 1030c82b795aa07fb202c5c926080593e9f6f7f6 SHA-256: 3b686e1e40a6d87ff131a2cabf2f3d2e6fc1ec6eeea3b9948edc0b33900bea86
186 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many hosted on disposable domains, suggesting a link farm or phishing lure. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically identified as phishing. While no scripts were directly extracted, the PDF structure and embedded URLs point towards a phishing attack designed to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 6

  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://nipisod.ru/strik?utm_term=what+is+the+origin+of+the+word+etymology
    • http://lnstagramverifiedbadge-media.com/vimamilagrk6u3.pdf
    • https://cdn-cms.f-static.net/uploads/4470678/normal_6040e16ecbe59.pdf
    • http://damvglaz0.xyz/fapesinumafiwuputo04u0z.pdf
    • http://deemonatrafik.xyz/automatic_flight_control_system_helicopter61216.pdf
    • http://tophomework.space/b._ed_syllabus40y6z.pdf
    • https://cdn-cms.f-static.net/uploads/4485718/normal_6033cc4131261.pdf
    • http://busurman.space/dog_licks_screen_video_lwpl7cfmj.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://c3d762b3-5d50-4891-ab6d-43710edd2423.filesusr.com/ugd/3254bf_abc5036b51bc40c7a8f3e0c3e83752e2.pdf?index=true
    • https://a1c9bafd-2917-4c1b-b79c-a4b44a941470.filesusr.com/ugd/f0f215_e66c3351da204a44abf73199ac845e54.pdf?index=true
    • https://748e6e98-33e2-4bd1-95aa-01ea3505a154.filesusr.com/ugd/704f6c_0e18f4f16a614715817f23874ff9456e.pdf?index=true
    • https://s3.amazonaws.com/zuponefi/sedixegamegutasavo.pdf
    • https://39c1d623-eccb-4af0-a86a-15328a2d61f9.filesusr.com/ugd/3cb6cb_d20ce6d0df9d4ed49dd8c5498866d107.pdf?index=true
    • https://83d12552-0bc1-4415-b221-1da25caacb9b.filesusr.com/ugd/1e11d0_e96948d3991143d886366dcafe7bfd2f.pdf?index=true
    • https://97a45c9e-1ab5-462a-bfe2-fded34b9a8b9.filesusr.com/ugd/b50c55_bbd0180e8a234b479e3dc55f5dda48aa.pdf?index=true
    • https://s3.amazonaws.com/sefepugolupalax/frommer_s_travel_guide_maui.pdf
    • https://13a7c488-548c-4b48-b567-d2b0b9a3e1de.filesusr.com/ugd/85d67f_b189f18e0f4c401e9347d08db601c542.pdf?index=true
    • https://s3.amazonaws.com/xajowu/concepto_de_criminologia.pdf
    • https://s3.amazonaws.com/fizup/grant_acquittal_audit_report.pdf
    • https://b5526579-b22d-45a0-8251-9885a72cf3eb.filesusr.com/ugd/0cd019_b48d1d4e24354aeaa7b041ba401b02f5.pdf?index=true
    • https://6a421494-2577-4416-904f-e17348f56b63.filesusr.com/ugd/85e76a_dd49d710cd60468986c20bad3b7ff95b.pdf?index=true
    • https://98cdd5c5-c43e-49eb-9373-39517e896cbb.filesusr.com/ugd/90661f_71631a56e23747f88e80776491f84b66.pdf?index=true
    • https://b27aca93-056c-4dd2-83a6-fd909c9f709d.filesusr.com/ugd/2ba3ac_ebca4eabaec94737973c1a29e83919e6.pdf?index=true
    • https://72cee60b-533f-4fda-9f40-87b1bb6f0553.filesusr.com/ugd/590778_7e6cd54557ea4b398164cb7c065cda47.pdf?index=true
    • https://s3.amazonaws.com/niwotipugonuvoz/juvukosogikesitijoz.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f57b.bin
a1ad06a5580492a4e3aff95450136b3d31b28de01d1fb878034e1d171d0f7be7
pdf-font-stream PDF embedded font (sfnt) at offset 0xF57B 5528 bytes
font_01_sfnt_off0001083c.bin
9da97cd1ae8730cbe06118ab382aa11accda120ed2a38ac78305088b9756251e
pdf-font-stream PDF embedded font (sfnt) at offset 0x1083C 10492 bytes
font_02_sfnt_off00012bf5.bin
2d9c180a6d8aee1cb9ff5761edd04753ca4edc5728f0ae0501a2d04c3ddcaf65
pdf-font-stream PDF embedded font (sfnt) at offset 0x12BF5 17540 bytes