Malicious PDF — malware analysis report

Static analysis result for SHA-256 72b685bf7b68fb7c…

MALICIOUS

PDF

81.8 KB Created: 2021-09-19 03:58:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: b9b1fe840483fba01db6baf61e0ac56d SHA-1: ab4451614a6c54124af6f5106560ef3497229c4b SHA-256: 72b685bf7b68fb7c679e63f0fa915e4070384cfb1467c575ec6913fe0809281a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with numerous external URIs pointing to potentially compromised or disposable hosting sites. The embedded URLs suggest the document's primary purpose is to redirect users to malicious content, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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
  • 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 https://coretry.ru/uplcv?utm_term=watch+boarding+house+2 PDF link annotation
    • https://khmernative-rice.com/userfiles/file/41197043935.pdfIn PDF document text
    • http://soepcentrale-dekeyser.be/userfiles/file/50920996811.pdfIn PDF document text
    • http://backupcenters.com/userfiles/file/89754581056.pdfIn PDF document text
    • https://gea99.com/ckfinder/userfiles/files/lowuposo.pdfIn PDF document text
    • http://kadh.kr/bobod/upload/file/40643934091.pdfIn PDF document text
    • http://cosmik-kinoteatr.ru/sadm_files/90121042784.pdfIn PDF document text
    • https://menokatea.com/ckfinder/userfiles/files/83341059992.pdfIn PDF document text
    • http://casadiriposomarsala.it/userfiles/files/30748209419.pdfIn PDF document text
    • https://gonguyenkhoi.vn/upload/files/84634065841.pdfIn PDF document text
    • http://pattarasawat.com/ckfinder/userfiles/files/5635462036.pdfIn PDF document text
    • http://www.gpkoaee.ru/ckfinder/userfiles/files/24708890416.pdfIn PDF document text
    • http://sasnowosielski.com/ckfinder/userfiles/files/movujixanafurekamivuwipil.pdfIn PDF document text
    • http://xingyeknitting.com/userfiles/files/jazaranezuj.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613da8049c1ca---11238203187.pdfIn PDF document text
    • http://scsychem.com/upload/files/pupilofofamukav.pdfIn PDF document text
    • http://landia-print.com/pdir/file/76248745255.pdfIn PDF document text
    • http://anhuizpyy.com/upload_fck/file/2021-9-12/20210912015744279718.pdfIn PDF document text
    • http://zpkprzemysl.pl/ckfinder/userfiles/files/gepulewupodupoja.pdfIn PDF document text
    • http://xn--80aaeiengkwpz6p.xn--p1ai/pub/file/taxalenisitesozunoxazusav.pdfIn PDF document text
    • https://sakesushimn.com/userfiles/files/risulesujajoxutipa.pdfIn PDF document text
    • https://jaunimodienos.lt/wp-content/plugins/super-forms/uploads/php/files/qjt1b993796nppee4rue6ufo2c/47878673469.pdfIn PDF document text
    • https://mindweave.co.uk/wp-content/plugins/super-forms/uploads/php/files/tfsu1r09outf8qd1b6fqubeo77/roterebopa.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_off0000dadb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDADB 17360 bytes
SHA-256: 7c7541d9e9c7628147d290d1774e240f176d28ff91328c1115a58f2a2b8b707d
font_01_sfnt_off0001081d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1081D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012034.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12034 10956 bytes
SHA-256: de7e69bdb3ba0a9ea2f0ad7609eb0391329c8590339bc3268a8341c4f6580dbf