Malicious PDF — malware analysis report

Static analysis result for SHA-256 687db665260f218d…

MALICIOUS

PDF

87.7 KB Created: 2021-04-08 20:58:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-14
MD5: c26e136a961859cd6147595189e07400 SHA-1: 151c91f6bf7f1ea58c644838079dfcede46b830a SHA-256: 687db665260f218dddde939bd6a305359f3904a057061dcaa6aa960ee5afe045
186 Risk Score

Malware Insights

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

The PDF contains a significant number of external links, many pointing to disposable domains, indicative of a link farm designed to host malicious content or phishing pages. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the PDF structure itself is used to facilitate the attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • 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.
  • 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://midufefew.ru/strik?utm_term=alexander+hamilton+book+pages PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4474739/normal_5fde13788587d.pdfIn PDF document text
    • https://cdn.sqhk.co/mosugukasiba/iGxajep/48802546278.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4489852/normal_604e4ed6bb730.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4392660/normal_5fe76b2750a7e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4371005/normal_5fdbcc820a44b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4409425/normal_5fd3d5646fd28.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4484631/normal_604a7477548ea.pdfIn PDF document text
    • http://dikegebe.mygamesonline.org/does_the_total_money_makeover_work.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4391620/normal_5ff55b305ddc1.pdfIn PDF document text
    • https://cdn.sqhk.co/lusikagidet/Qoahfhc/chengdu_metro_map.pdfIn PDF document text
    • https://cdn.sqhk.co/furigelo/v1PWDhh/batudefegiwafibaguzawew.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://nosigegu.onlinewebshop.net/what_is_the_sum_of_exterior_angles_of_a_regular_polygon_of_nine_sides.pdfIn PDF document text
    • http://nodikaduf.onlinewebshop.net/binomios_con_termino_comun_ejercicios.pdfIn PDF document text
    • https://23751d96-d7b3-42ca-b8ca-e459b671ea95.filesusr.com/ugd/7de994_2d2c02a98d28460785a0ef9ed4813a40.pdf?index=trueIn PDF document text
    • https://1f9cfe0c-d655-4514-b58a-75380282e405.filesusr.com/ugd/d31784_307547d75bbe4f2c9f9532c7f314d3a3.pdf?index=trueIn PDF document text
    • https://ca39a19f-16f9-469f-ab0b-65ec0463b8d0.filesusr.com/ugd/cc9b97_7e1628e2bfaf431aa832f8cb9db2c234.pdf?index=trueIn PDF document text
    • https://42cc6f6d-9125-48bc-bce4-1bf15f49b1be.filesusr.com/ugd/7c30af_e5e9f612f04348d2a1331e5c1bba4f51.pdf?index=trueIn PDF document text
    • https://b1394492-4877-47b1-8bf2-e962974baa99.filesusr.com/ugd/3e4b7a_ba4bc42caca14a098be3ccf480b8ad93.pdf?index=trueIn PDF document text
    • https://f6b99bba-f064-431f-ab68-6eacb91b2703.filesusr.com/ugd/35e1ce_5fc990f399b348cf869649635a0b6ab0.pdf?index=trueIn 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_off0000f8f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8F0 5636 bytes
SHA-256: cec7300aaf694e7073da2a46c00414cf7f585d7171c433efad630dfa55bf2ee0
font_01_sfnt_off00010bef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BEF 11992 bytes
SHA-256: 700b82662dfcbb4850e6be2f566fdb8c8fad69e482990d0b640924d809569489
font_02_sfnt_off000133ef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x133EF 18036 bytes
SHA-256: 8d30ced5f5af3a440d19a1bf21320842e6ba889631b6ad75cdf004366c21f183