Malicious PDF — malware analysis report

Static analysis result for SHA-256 4a9f172c24077097…

MALICIOUS

PDF

83.5 KB Created: 2021-04-24 22:37:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: b122ebb9fb591e4ea2b80cc5024b4ed4 SHA-1: ecef8ae4230281a38a7436b79da6163205e1a162 SHA-256: 4a9f172c240770974a15c02f41a7bf80aebf1b1de639e242c2e5acd061918c78
126 Risk Score

Malware Insights

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

The PDF contains multiple heuristics indicating malicious intent, including external URI links and a link farm on disposable hosting. The ML classifier and ClamAV detection strongly suggest this is a phishing or trojan delivery mechanism. The document body, though heavily obfuscated, contains text related to quotes and the authoring application, which is likely a lure to direct users to the malicious URL.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

Heuristics 5

  • 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://resalured.ru/strik?utm_term=smile+even+though+it+hurts+quotes PDF link annotation
    • https://cdn.sqhk.co/ziloteduxemo/ghg1Fhi/59879925369.pdfIn PDF document text
    • http://yewes.space/89851842009zfp3l.pdfIn PDF document text
    • https://cdn.sqhk.co/tawavumazo/haYjdEE/78618135447.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4373259/normal_600d5c9ec7a12.pdfIn PDF document text
    • http://fastnoutservice.ru/que_es_un_retrato_escrito_y_sus_caracteristicasiai8r.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366024/normal_5fd241b315d88.pdfIn PDF document text
    • http://yewes.space/fixusedejusazisuba48tag.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4499995/normal_601cf4e5558cd.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4376852/normal_6018f5c2a0feb.pdfIn PDF document text
    • http://ideaita.fun/maxonosimebufinuvizusina14gec.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://4a1fbaa0-0e67-401b-a466-96699e2e5642.filesusr.com/ugd/9647bf_18ab30af96a84ce6bc9d18bdb2f3ea34.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/paxivogedewilu/letters_and_their_sounds.pdfIn PDF document text
    • https://d128792e-e0a8-46e0-98ed-b941f5da69b2.filesusr.com/ugd/b98abb_877cd3191976478c8af219f8ceab3790.pdf?index=trueIn PDF document text
    • https://60b161a2-b511-46bc-b48c-7ca4331f2db3.filesusr.com/ugd/34b71b_05fc5573fff6414684645644ab4b1731.pdf?index=trueIn PDF document text
    • https://c3e780e1-a1ee-422e-80b3-2bf79490ff1e.filesusr.com/ugd/dc7b26_399313a1de4d4b289449d80522774397.pdf?index=trueIn PDF document text
    • https://a1b876fd-e98f-4594-996d-fc523792ae9e.filesusr.com/ugd/efcbf0_7db57afba8f846758ca15435da21ae7e.pdf?index=trueIn PDF document text
    • https://314f4944-3dd9-45af-b5ee-fc7f46c963e4.filesusr.com/ugd/73cb9e_a7f205176b0b4850a76e1af20af709e2.pdf?index=trueIn PDF document text
    • https://972af30b-04c2-4618-b911-83ba0b7fef9e.filesusr.com/ugd/84a5c6_6afa1fea5a524dd4a827e9d9512fd7da.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/murudute/56818340575.pdfIn PDF document text
    • https://s3.amazonaws.com/jazofi/used_2018_toyota_camry_for_sale_in_nigeria.pdfIn PDF document text
    • https://s3.amazonaws.com/dewazewokib/flowers_in_the_attic_book_set_order.pdfIn PDF document text
    • https://1682489e-d94b-4f22-b6a6-c8ecb623ca2e.filesusr.com/ugd/5f226e_9c10e4282c494fdcb0e29c8d95db0142.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/liluvad/wutilirudenito.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
    • 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_off0000f2b9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2B9 5180 bytes
SHA-256: 76a17ce98d8961f9153d60da1eb961c2e5a413b3124318b513fd9e33b405c3d4
font_01_sfnt_off0001042f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1042F 10492 bytes
SHA-256: 6694ce998e238088b7059cfefb15adc0794ccb315ac9dc148249b6ce450512df
font_02_sfnt_off000127dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x127DD 16620 bytes
SHA-256: 19a7050b65015e5669bc232af8f32476a5d7f98671b2fc60e607b44b8d1f9ffe