Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa70bcbf1a451975…

MALICIOUS

PDF

83.4 KB Created: 2021-09-16 14:33:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: f50d147b08ce053411a58be55ca07e94 SHA-1: 150fa42c326b6629649fc0a12104d575b889c110 SHA-256: aa70bcbf1a4519757ac550d1ebb8af11dc51b4be7ffc56f345febfd844ccb3ba
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded links, many pointing to disposable domains, and is flagged by heuristics as a link farm. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and link farm heuristic suggest it's designed to redirect users to malicious sites, potentially for credential harvesting or further payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 http://silarperu.com/UserFiles/file/jixasulezejagulawog.pdf In PDF document text
    • http://np-laser.com/upload_fck/file/2021-9-9/20210909015419699453.pdfIn PDF document text
    • http://www.moyekolodin.com/files/97939431465.pdfIn PDF document text
    • http://gdlianyu.com/uploadfiles/file/tekun.pdfIn PDF document text
    • http://svx.su/ffile/file/kuxodetelerenizusedoj.pdfIn PDF document text
    • http://ossokahve.com/upload/file/geredene.pdfIn PDF document text
    • http://galettedesrois.hu/userfiles/file/94488791130.pdfIn PDF document text
    • https://sogelec-eng.com/files/ckfinder/files/futunivutaxujitig.pdfIn PDF document text
    • http://rudolphi.nu/userfiles/file/lujor.pdfIn PDF document text
    • http://www.patriarca-batiment.com/ressource/site-image/files/viluxogixunujerakejuk.pdfIn PDF document text
    • http://elma1.ru/!upload/files/33057354183.pdfIn PDF document text
    • https://art-gallery.mn/uploads/files/75353795934.pdfIn PDF document text
    • https://indiantalentjunction.com/milan/media/gokupax.pdfIn PDF document text
    • https://kimtuong.vn/isc/public/files/fckupload/file/35765414262.pdfIn PDF document text
    • https://chogmai.org/ckfinder/userfiles/files/32071392600.pdfIn PDF document text
    • https://corpus.bg/files/fck/file/masatekero.pdfIn PDF document text
    • http://identik.hu/editor_up/jigosazesepagadakajesuve.pdfIn PDF document text
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/161319afe1ff17---50789339376.pdfIn PDF document text
    • http://kcemsp.org/upload/editor/file/bawobeletabok.pdfIn PDF document text
    • https://satnamunicipalcorporation.com/admin/ckfinder/userfiles/files/38216312005.pdfIn PDF document text
    • http://niezapominajkowo.eu/userfiles/file/99865523686.pdfIn PDF document text
    • http://lucidarepavimentimarmogenovaealessandria.it/userfiles/files/2895745564.pdfIn PDF document text
    • https://messianic.live/wp-content/plugins/super-forms/uploads/php/files/f8f9f1b4509c0a49515df14738ef285b/tokifivizomutozep.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=xiaomi+mi+note+10+lite+proximity+sensor+fixPDF link annotation
    • 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_off0000defb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEFB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f712.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF712 10916 bytes
SHA-256: 285f79d00eb1461655aa5654d72e708993354ae6deeba0c01003279b75c5832d
font_02_sfnt_off0001105a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1105A 18508 bytes
SHA-256: abf2f5d14aa99442a4b61b53eb33f8faa1fd34f67e502bcc7bd6f4d2dcf56655