Malicious PDF — malware analysis report

Static analysis result for SHA-256 91d9429191f0a820…

MALICIOUS

PDF

84.3 KB Created: 2021-09-19 19:07:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: c1f2dddadcfe53da2f2027a6e9db0170 SHA-1: 81a433ef619e5a52636287315731a4f197fed5af SHA-256: 91d9429191f0a82049e0cf13b9dfade44b7173109bd410d16234c1a67b10f1b6
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many of which are hosted on disposable domains, suggesting a link farm or phishing lure. The presence of external URIs and the PDF_SEO_DISPOSABLE_LINK_FARM heuristic strongly suggest the file is designed to redirect users to potentially harmful websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

Heuristics 5

  • 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 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://dakhoanhanai.com/images/files/dasaduj.pdf In PDF document text
    • https://efsanepin.com/calisma2/files/uploads/27856746284.pdfIn PDF document text
    • https://srmhomes.com/images/bulk_images/files/97584315100.pdfIn PDF document text
    • https://apatity.verlauf-ekb.ru/admin/ckfinder/userfiles/files/60566794032.pdfIn PDF document text
    • http://pwmtqatar.net/userfiles/file/bawejemamoxevu.pdfIn PDF document text
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/16143f17c2c055---44843078300.pdfIn PDF document text
    • http://gandolfiarchitetti.com/userfiles/files/740483769.pdfIn PDF document text
    • http://kxxbs.com/uploadfiles/file/a/81822164240.pdfIn PDF document text
    • http://alibabashipping.com/userfiles/file/fefekal.pdfIn PDF document text
    • http://zhizhencn.com/filespath/files/20210911105439.pdfIn PDF document text
    • http://88cpap.com/userfiles/files/16407841124.pdfIn PDF document text
    • https://spirit-legend-enterprises.com/webroot/editor-uploads/files/tamexosoxi.pdfIn PDF document text
    • http://hindustanadvancedsolution.com/t/tutorfirm/uploads/ck/files/lonep.pdfIn PDF document text
    • http://onsijsselstein.nl/userfiles/files/bidazijoviki.pdfIn PDF document text
    • http://gocep.org/data/userfiles/files/fegibe.pdfIn PDF document text
    • http://imreelectric.sk/uploads/file/gezoripawisibupobazif.pdfIn PDF document text
    • http://autoscuolemontagna.it/userfiles/files/gikowaloxawudubivus.pdfIn PDF document text
    • http://huynhgiabaohotel.com/uploads/FCK/file/nozesuzinenotibudowanisi.pdfIn PDF document text
    • http://herningbadintra.dk/app/webroot/upload/files/nixaf.pdfIn PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/16140b90bbbe96---87613956718.pdfIn PDF document text
    • https://worldcastlive.com/userfiles/file/kazudot.pdfIn PDF document text
    • http://medtravel.lv/images/hand_uploaded/files/44162959022.pdfIn PDF document text
    • https://yarpaket.ru/userfiles/file/29768874312.pdfIn PDF document text
    • http://alles-vom-schreiner.de/userfiles/file/sujavanurimurugenufulu.pdfIn PDF document text
    • http://uforoi.com/app/webroot/uploads/files/wosibibakitarevadu.pdfIn PDF document text
    • https://cargotavio.ru/files/file/9245774831.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=change+chrome+theme+androidPDF 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_off0000df98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF98 10632 bytes
SHA-256: 0626203691cdcd0e93d26eedac2d81a162fb0c3d2675cd594d58aadd7ada8429
font_01_sfnt_off0000f784.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF784 20260 bytes
SHA-256: 25b8f8a291f5b16576bcfcb0ef45eb3bec265cc441c6d30e90140816da64bb78
font_02_sfnt_off00012bc5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12BC5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1