Malicious PDF — malware analysis report

Static analysis result for SHA-256 bc638951b03c2d0b…

MALICIOUS

PDF

83.9 KB Created: 2021-09-18 21:17:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 2776e525adeb8995e34cfab07941da21 SHA-1: 7e93a9e6ae48630834c3c3441b4d03410cfac386 SHA-256: bc638951b03c2d0b1c13376f2c8eb9a458217248303eb536bad1853580c30798
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is identified as malicious by ML classifiers and ClamAV, with heuristics indicating it functions as a link farm on disposable hosting. The PDF contains numerous embedded URLs, many of which point to potentially malicious domains. While no scripts were explicitly extracted, the PDF structure and embedded URIs suggest an attempt to redirect users to external content, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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://laptopcuhaiphong.vn/upload/files/76598016462.pdf In PDF document text
    • http://5mal4.de/moneyvidya/web/images/userfiles/file/38908985754.pdfIn PDF document text
    • http://hzqljsj.com/images/upload/File/fiviwe.pdfIn PDF document text
    • http://www.satit.nrru.ac.th/satit/_Adminis/ckfinder/userfiles/files/fajowu.pdfIn PDF document text
    • https://lompatjauh.com/contents/files/58009246787.pdfIn PDF document text
    • https://primer-spb.ru/files/files/wakirotefaseso.pdfIn PDF document text
    • http://ozkayalarlojistik.com/userfiles/file/desevovu.pdfIn PDF document text
    • http://kartelabasligi.com/images_upload/files/37926375867.pdfIn PDF document text
    • http://tygodnikzuzlowy.pl/ckfinder/userfiles/files/44169311348.pdfIn PDF document text
    • http://kielcenoca.pl/files/file/88018132085.pdfIn PDF document text
    • http://torby.kbo.pl/ckfinder/userfiles/files/41304229574.pdfIn PDF document text
    • https://happen.webasl.com/userfiles/file/48431647441.pdfIn PDF document text
    • http://tsg-edinstvo.ru/userfiles/file/dubotoligasewodozikavaga.pdfIn PDF document text
    • http://erbamedica.org/userfiles/files/gusaduwodisunuvalovubot.pdfIn PDF document text
    • https://alasclub.gr/neuro/ckfinder/userfiles/files/nevezugila.pdfIn PDF document text
    • http://www.barankayalar.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1613b5cbfada0c---dogezanekire.pdfIn PDF document text
    • http://standdominica.org/files/files/41460294259.pdfIn PDF document text
    • http://kotolantopeni.cz/file/72898796321.pdfIn PDF document text
    • http://planet-for-events.de/userfiles/file/mamefomuvig.pdfIn PDF document text
    • https://pikhospital.com/ck_uploads/uploads/files/viratofenidato.pdfIn PDF document text
    • https://okazionche.com/files/nizonisuzo.pdfIn PDF document text
    • http://saga.diamonds/uploads/ckfinder/files/bojidu.pdfIn PDF document text
    • http://aias.pnu.ac.th/ckfinder/userfiles/files/9512414445.pdfIn PDF document text
    • http://www.onegelha.com/wp-content/plugins/super-forms/uploads/php/files/017e2f8b15ecc777ed107c71005b6434/rafifafitavimudinexod.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/S30rS-6n6vg/uplcv?utm_term=formula+cartoon+all+stars+apkPDF 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_off0000dbdb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBDB 10480 bytes
SHA-256: 66dc603c834740ea5e58e681e6180dc20f949252661c26404c4873e754c50a22
font_01_sfnt_off0000f3b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3B0 20976 bytes
SHA-256: 3b5d2256d05df0073e395c10814ee885b4f74bd643e75ef67d0a9fe81b9c5a72
font_02_sfnt_off00012a1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A1C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1