Malicious PDF — malware analysis report

Static analysis result for SHA-256 821c090b4b723b6c…

MALICIOUS

PDF

133.2 KB Created: 2021-03-30 05:28:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: ed063c92463b320f461809fbe919fc54 SHA-1: 9b4a25e798a7d8a695875f2f0408e8e010f83c03 SHA-256: 821c090b4b723b6c920cf8938a5310cd90f6ef5c87c45eaef17337b9abdbcaf9
202 Risk Score

Malware Insights

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

The PDF contains numerous invisible links, with one prominent URL pointing to a CAPTCHA-themed lure. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of embedded URLs and the nature of the heuristics suggest this PDF is designed to lure users to external sites, potentially for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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.
  • Invisible PDF links to CAPTCHA-themed web lure high PDF_CAPTCHA_LINK_LURE
    PDF contains invisible clickable link annotations that point to a CAPTCHA/capcha-themed web path. This is a common phishing and ClickFix-style routing pattern: the PDF itself is inert, while the linked page performs the credential prompt or fake verification.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://dugedepap.ru/123?utm_term=captchatypers+android+app In PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/d2010ba9-2999-42f9-b94e-cd1bfb4c4f34/can_a_samsung_s9_plus_screen_be_replaced.pdfIn PDF document text
    • https://s3.amazonaws.com/dosalapasenow/14328361214.pdfIn PDF document text
    • https://s3.amazonaws.com/vojapu/ensayo_argumentativo_sobre_el_aborto.pdfIn PDF document text
    • https://s3.amazonaws.com/vaxebisapesi/vavigajupid.pdfIn PDF document text
    • https://s3.amazonaws.com/zumezeviwakiz/guideposts_book_series.pdfIn PDF document text
    • https://s3.amazonaws.com/rorives/renunciation_of_executor_form_uk.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6f79fdac-0454-4f66-a080-220a3699a652/60771507959.pdfIn PDF document text
    • https://691dfa98-c543-4342-b77d-a3d7fbf094aa.filesusr.com/ugd/d55835_129319b626d94fca921c0045ee2b9f5a.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/supefujoxopubu/kakamimipij.pdfIn PDF document text
    • https://s3.amazonaws.com/farefasejikap/expense_sheet_template_in_excel.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/423b55e3-dbd2-48ac-8076-a3848207c7d1/88810538886.pdfIn PDF document text
    • https://s3.amazonaws.com/muvojugejoxip/wiril.pdfIn PDF document text
    • https://s3.amazonaws.com/xisefowu/8105135329.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/23bcc738-472e-4f86-b93a-d8262afd34be/13061752763.pdfIn PDF document text
    • https://s3.amazonaws.com/wivunonovef/mental_maps_of_reality_examples.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/51a3e70e-532a-4ee8-b057-3cb876ec3577/docker_cli_windows_install.pdfIn PDF document text
    • https://3eeb541e-75be-486c-a732-b1e279b2a932.filesusr.com/ugd/eaab1c_fdfd7c39ae6541fab666495a60de8e25.pdf?index=trueIn PDF document text
    • https://cb2d4818-2134-4ea5-ae57-1bc45cfc4292.filesusr.com/ugd/7e787c_e5877d8a3255416289006cf860dcb0ce.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/xunilukegez/96634394000.pdfIn PDF document text
    • https://s3.amazonaws.com/jazofi/wopuwipoforuxodorawanumi.pdfIn PDF document text
    • https://ad858f6a-7bbb-416d-9365-e04d7986ed9b.filesusr.com/ugd/3c9ac1_c4a343f32a234c71a23e033c67bdd108.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/f5c60deb-0029-4155-a01e-bc570c78f3af/les_3_mousquetaires_dessin_anim_episode_25.pdfIn PDF document text
    • https://s3.amazonaws.com/rufonali/86169470351.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001cf18.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1CF18 5136 bytes
SHA-256: cf19b1e716bc4bcc6e5a97920a1a443e1ed6e29347d345694218d9d428437593
font_01_sfnt_off0001e08a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1E08A 11528 bytes
SHA-256: 4dd18a931a6dea51552230033cfbbc57132be2734d9ba876e5a569b8fb3498ed