Malicious PDF — malware analysis report

Static analysis result for SHA-256 639621ea633cae7d…

MALICIOUS

PDF

89.7 KB Created: 2021-03-23 11:27:25 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 2578374a55a18e9cb83d8eb2c937a024 SHA-1: d5c8ca62627fc6d042280e2f4f570dfd7cdaceef SHA-256: 639621ea633cae7dc4a338ac37d1df5da2337b193a6cb87b6dc06a1dc2b35258
236 Risk Score

Malware Insights

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

The PDF document contains numerous links, many of which are part of an SEO link farm designed to redirect users to various websites. One heuristic specifically identifies a link farm with 30 external PDF links, and another points to a redirector for 'free-download phishing'. The ML classifier and ClamAV detection strongly indicate maliciousness. The embedded URLs and the nature of the heuristics suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://gimoguvi.ru/award?keyword=the+art+book+big+ideas+simply+explained+pdf PDF link annotation
    • https://komamezumef.weebly.com/uploads/1/3/1/3/131398541/leparobasub_wulewezaxe_nakerujutijusas.pdfIn PDF document text
    • http://rojepaj.iblogger.org/70788413529.pdfIn PDF document text
    • http://tesepaxe.iblogger.org/pofibonefa.pdfIn PDF document text
    • http://golesaluwo.66ghz.com/buzarirerobenefexiraneb.pdfIn PDF document text
    • https://motixovelubebov.weebly.com/uploads/1/3/6/0/136085904/9391d0a2c9d.pdfIn PDF document text
    • http://vuzitofakomuj.22web.org/96114014666.pdfIn PDF document text
    • https://wadasowodasi.weebly.com/uploads/1/3/5/3/135316150/lufom_woson_pufif_sexabid.pdfIn PDF document text
    • http://fitixezuveseli.22web.org/kipadanopoteribogodefi.pdfIn PDF document text
    • https://pavonaxasove.weebly.com/uploads/1/3/5/3/135310158/dugesivenasudu_netefesuvowig_wekugutalefij_zesoxewoj.pdfIn PDF document text
    • https://vogavova.weebly.com/uploads/1/3/1/6/131606390/2865a.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://s3.amazonaws.com/baxekojojexusol/best_sale_on_beats_pill.pdfIn PDF document text
    • http://bukuzagalu.rf.gd/is_eating_ice_chips_bad_for_your_teeth.pdfIn PDF document text
    • https://s3.amazonaws.com/wovugi/gisesopaturatisivep.pdfIn PDF document text
    • http://temalefedamoj.epizy.com/error_o._s._b._d._loggingfailureanalysisreporter.pdfIn PDF document text
    • https://s3.amazonaws.com/rutufokedizon/pipazoxuzejipipalaf.pdfIn PDF document text
    • https://s3.amazonaws.com/degisapemifa/serrate_suture_information.pdfIn PDF document text
    • http://wazikaje.rf.gd/61222280313.pdfIn PDF document text
    • https://s3.amazonaws.com/wegugus/64594577818.pdfIn PDF document text
    • http://muzezal.rf.gd/assassins_creed_1_highly_compressed.pdfIn PDF document text
    • https://s3.amazonaws.com/legobegutulo/chain_reaction_game_free.pdfIn PDF document text
    • http://mesuwirafifi.rf.gd/mr._bean_holiday_movie_in_tamilrockers.pdfIn PDF document text
    • http://tezipibuboxigo.epizy.com/xulefo.pdfIn PDF document text
    • https://s3.amazonaws.com/suxuzubojut/why_cheat_india_full_movie_pagalworld._com.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fbfc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBFC 5568 bytes
SHA-256: b4e10135bd5b8f2063d6f5254c374bbb75506f0412e30a3141d2085fe4c743a5
font_01_sfnt_off00010eca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10ECA 5896 bytes
SHA-256: 27facea08f760b6c9ccffc63dc3354f6ddb502aa9495885ea4bb65c44df333a7
font_02_sfnt_off00011f1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F1C 15520 bytes
SHA-256: 6a508e51bfc42bea9cbcb0469d3b5e21f9cfd7ca8a8ad923fed9eef36cac5f63
font_03_sfnt_off00014a89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14A89 4324 bytes
SHA-256: d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378