Malicious PDF — malware analysis report

Static analysis result for SHA-256 a98198d4ed0b7623…

MALICIOUS

PDF

69.1 KB Created: 2021-09-29 00:23:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 0158d069581db7fd52236c4da73a1639 SHA-1: 033c109cf7bf17e51cb4dc644e426f26e2535cbf SHA-256: a98198d4ed0b7623e6752c8624dae858395cbf0a8a62583e2b1ba391ff461c07
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs pointing to various domains, many of which are identified as compromised or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution through these links. The file's structure and URL patterns are consistent with a link farm designed to obscure the final destination.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://constantemails.com/userfiles/file/163084023528754285851.pdf In PDF document text
    • http://albino-pitti.com/pub_img/file/40999070393.pdfIn PDF document text
    • https://birudongker.com/contents/files/25709820914.pdfIn PDF document text
    • https://bhavanarayanaswamy.org/userfiles/file/wobumadozulovu.pdfIn PDF document text
    • https://storage-in-motion.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ff744856cc---49667732168.pdfIn PDF document text
    • http://nhakhoauytinhaiphong.com/upload/files/nikakezilesifumifimogoj.pdfIn PDF document text
    • https://worldkelo.com/wp-content/plugins/super-forms/uploads/php/files/f6e1fdd5bcd87d7766646d1bdb90b580/80890104046.pdfIn PDF document text
    • http://kredoteka.ru/uploads/file/25068262468.pdfIn PDF document text
    • https://www.inter-tube.co.uk/wp-content/plugins/super-forms/uploads/php/files/3bf7b002aaa1f2a6c3d71cd10096520f/38714211877.pdfIn PDF document text
    • https://mikludava.lt/images/files/45202871592.pdfIn PDF document text
    • http://elma-itc.ru/!upload/files/pezosomojakizegugadote.pdfIn PDF document text
    • http://www.xn----9sbkvfu2aex3d.xn--p1ai/ckfinder/userfiles/files/zujimatinixirodusitute.pdfIn PDF document text
    • http://profiklub.sanswiss.cz/files/file/32543700773.pdfIn PDF document text
    • http://cngwalk.com/fckeditor/userfiles/image/nawazavabepukeraze.pdfIn PDF document text
    • http://kamerton.nl/clientfiles/kepobiruvi.pdfIn PDF document text
    • http://belv.ru/userfiles/file/wasifoka.pdfIn PDF document text
    • http://shethof.ch/cgi-bin/dynamisch/file/getuwif.pdfIn PDF document text
    • http://seteo-dechets.com/images/file/87077783144.pdfIn PDF document text
    • https://adian.eus/files/galeria/files/44855134565.pdfIn PDF document text
    • http://xatrbio.com/userfiles/file/60997367466.pdfIn PDF document text
    • http://chi-kara.net/userfiles/file/religeguvolatemu.pdfIn PDF document text
    • https://taipeitccia.org/CKEdit/upload/files/41198249236.pdfIn PDF document text
    • https://keyword-lda.pt/site/upload/file/fureroxoxawika.pdfIn PDF document text
    • http://monthclean.com/uploads/files/202109060718238988.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=android+dengan+baterai+5000+mahPDF link annotation
    • http://alessandrotria.altervista.org/areap/ckfinder/userfiles/files/45079759451.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_off0000affe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAFFE 10856 bytes
SHA-256: 519da90ccb3cba6de981cbe2a909d4165f1ec34898ca7c61cc5de34ced34307e
font_01_sfnt_off0000c8af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8AF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000e0c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0C1 15128 bytes
SHA-256: 5313a3026f22728278d168bf5aab9f492264bceccce4f55168798ce3936ad1b3