Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa770b33e590b52d…

MALICIOUS

PDF

82.3 KB Created: 2021-09-18 07:50:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 971860c25ce2d15759f49edcc7d1c1ff SHA-1: 26b8b62a73418342171605e9d55719513b23d008 SHA-256: aa770b33e590b52d6020c30a4a3f731eb010c401eadaf3a63b4411b81557dac2
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple links to external websites, with one heuristic specifically identifying a PDF link to an algorithmically-generated URL. This suggests the document is designed to trick users into downloading a secondary malicious file. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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
  • 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.
  • 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://crysiq.ru/uplcv?utm_term=filto+apk+download PDF link annotation
    • https://kitapkapla.com/upload/ckfinder/files/19929034493.pdfIn PDF document text
    • https://menlopark.com/wysiwygfiles/file/sobazeduzijoloreleru.pdfIn PDF document text
    • http://grimastone.ru/files/60162342144.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161451c852800c---lapozadeduvazunugejorevo.pdfIn PDF document text
    • http://unternehmensberatung-hegenbarth.com/userfiles/file/39892317884.pdfIn PDF document text
    • http://burelomdo.com/ckfinder/userfiles/files/sajerab.pdfIn PDF document text
    • http://oldmotorsclub.com/files/file/13544831780.pdfIn PDF document text
    • https://oykufestivali.com/ckfinder/userfiles/files/32002090198.pdfIn PDF document text
    • https://bbensonmft.com/wp-content/plugins/super-forms/uploads/php/files/9b79d5b7cafd2a1b48c0930f1c49b84c/51077820972.pdfIn PDF document text
    • http://edwardfmcgintypa.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/vuderobabigoxusak.pdfIn PDF document text
    • https://grupo-bahia-real-estate.com/ckfinder/userfiles/files/jubalojusa.pdfIn PDF document text
    • http://metabolitplus.ru/files/file/disenifizarok.pdfIn PDF document text
    • http://jingkangchem.com/upload/files/50019920957.pdfIn PDF document text
    • https://tungafilm.com/dorceiys/ckfinder/userfiles/files/65604340886.pdfIn PDF document text
    • https://mallarpurnaisuva.org/go/file/70234821167.pdfIn PDF document text
    • https://lerivagedesmilleetangs.com/caningest/images/file/55357723058.pdfIn PDF document text
    • http://s2ipower.com/survey/userfiles/files/dakaz.pdfIn PDF document text
    • http://ylgems.com/file_media/file_image/file/88169036541.pdfIn PDF document text
    • https://nguoixunghekiev.vn/userfiles/file/fometutube.pdfIn PDF document text
    • https://projectmine.hu/ckfinder/userfiles/files/tuzade.pdfIn PDF document text
    • http://www.miwon.com.vn/app/webroot/uploads/files/17155498202.pdfIn PDF document text
    • https://superiorservicesandsolutionsfl.com/nbloom/fckuploads/file/sowubumepe.pdfIn PDF document text
    • http://wakabaeducation.com/userfiles/file/moxopametad.pdfIn PDF document text
    • http://torgoborud.org/images/file/38333334083.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://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_off0000d8ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8EC 10140 bytes
SHA-256: 60003d4d4359e78cbb8fd2224f821a2ccec02edc394d9f6052d45804be8cd9c5
font_01_sfnt_off0000efae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFAE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000107c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x107C0 19728 bytes
SHA-256: 55b964fc7a9b5b8ddf955dc211034f86d85a0055f921ea8eb0e676de2ff6371d