Malicious PDF — malware analysis report

Static analysis result for SHA-256 39a955172b587118…

MALICIOUS

PDF

82.5 KB Created: 2021-04-08 07:11:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-23
MD5: 840e247e345680aeb3c3119506193c9a SHA-1: 1c0791083e0d13b14a51bf98ad3f9e47ff86eadc SHA-256: 39a955172b587118a3322b8d0b08b60c044bf532e1d5358c292450f28cd5e25a
186 Risk Score

Malware Insights

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

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 6

  • 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.
  • 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=cursos+de+ingles+online+con+certificado+oficial+argentina PDF link annotation
    • https://cdn.sqhk.co/moserusoba/elYckYJ/marco_s_garden_pizza_bowl_nutrition_facts.pdfIn PDF document text
    • https://cdn.sqhk.co/vasegodesazu/cGihAtJ/lezotiretilesapinigan.pdfIn PDF document text
    • https://cdn.sqhk.co/wezufunin/idhqrjI/29814351500.pdfIn PDF document text
    • https://cdn.sqhk.co/zumedizojas/dqWhehB/12182248462.pdfIn PDF document text
    • https://cdn.sqhk.co/polidupokasu/amifidT/46824572051.pdfIn PDF document text
    • https://cdn.sqhk.co/savekedeg/fprLijb/tezojowadopaletu.pdfIn PDF document text
    • https://cdn.sqhk.co/fogobewataja/5lMrNjf/17020904037.pdfIn PDF document text
    • https://cdn.sqhk.co/linidivez/ab3pDCN/moto_extreme_crazy_games.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4393904/normal_6000b1abbe909.pdfIn PDF document text
    • https://cdn.sqhk.co/zizaratijiga/1hjmujg/jiwetagejilewilita.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4370090/normal_5fc7b60e2d0ff.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4365608/normal_60048a5066621.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4366647/normal_6067215c385c9.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4464327/normal_5fecaef011c85.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4452851/normal_6004af57b7194.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417669/normal_604d17569b7a0.pdfIn PDF document text
    • https://cdn.sqhk.co/pimidima/jivhhon/50733113477.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://87c8fc71-818b-4167-bf0d-2ac3bc49ffd1.filesusr.com/ugd/f9d4cd_e3c9c9c6cd3e49b98e4c0c653b013cf5.pdf?index=trueIn PDF document text
    • https://a97be2a3-bfb5-42de-bba9-b145341b31aa.filesusr.com/ugd/1f2860_1b9bc7e3055a49ba9a8907f546e8623b.pdf?index=trueIn PDF document text
    • https://68358877-4ee6-4e53-94f7-4bd9665c1f53.filesusr.com/ugd/3bbd68_b542189d657f4859b4192ae7f12fd72d.pdf?index=trueIn PDF document text
    • https://2172aa7b-56d6-4bcb-a12f-aafeda7c7725.filesusr.com/ugd/0d9129_f131d96700af4364990cdea3c8fb74e9.pdf?index=trueIn PDF document text
    • https://3568c1c9-c281-4b9a-9ea9-d5d291e0176b.filesusr.com/ugd/e5d8db_1b7b7fcbc66e43d085528d73b86b3743.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_off0000e987.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE987 5092 bytes
SHA-256: 713170e96ad1f7e2b65ee12efc966f8df35d52b6c30621bae123a5b1e63aacac
font_01_sfnt_off0000fae6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAE6 12804 bytes
SHA-256: d4f9f2de550bbee41862b19c3393d0d621bab5c27b076d9a51bf6b82a1c22295
font_02_sfnt_off0001245d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1245D 16204 bytes
SHA-256: 541fa2b6826b0add99b7d5a173ef1e6a5567607b5192f75b810eb17d6a563501