Malicious PDF — malware analysis report

Static analysis result for SHA-256 b7fdf6ca7bda372a…

MALICIOUS

PDF

69.4 KB Created: 2021-10-02 19:03:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 7a8737114ea1bd69bec5e4d1bcd51a3f SHA-1: ab03a02f5090b1cbce0762df35c0679c5d93a895 SHA-256: b7fdf6ca7bda372a48413e041a7b702737f7eeeee0ed2b963be273f04fb9a795
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests the document functions as a link farm, directing users to numerous disposable hosting sites, likely to distribute further malicious content. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the heuristics point towards an attempt to trick users into downloading further malicious files, potentially via embedded JavaScript.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://decaiyun.com/upload/file/210913041234864879uuncazu6cufk.pdf In PDF document text
    • http://donauwell.at/userfiles/file/59460985362.pdfIn PDF document text
    • http://zetrade.cz/userfiles/file/xapamuxitit.pdfIn PDF document text
    • http://guojingmall.com/userfiles/file///28753668813.pdfIn PDF document text
    • http://midoriku.zaitakunet.jp/app/webroot/upload_images/files/jujefokanitanimopinam.pdfIn PDF document text
    • http://xn----7sbjvweekof5d.xn--p1ai/files/files/12822755539.pdfIn PDF document text
    • https://nenmongdangquang.com/upload/files/10129117887.pdfIn PDF document text
    • https://haps.company/wp-content/plugins/super-forms/uploads/php/files/33fbdceb7d0f22cda5c377f79b04ae7b/nitewezumar.pdfIn PDF document text
    • http://piazzademarini3ge.com/userfiles/files/5634687169.pdfIn PDF document text
    • https://vibangthuaphatlai.net/uploads/files/fiwomufoxigerozokeposo.pdfIn PDF document text
    • https://stabiactiv.com/userfiles/file/xoriwisigakowusavoxogi.pdfIn PDF document text
    • http://xn----7sbbbizu2bxaod.xn--p1ai/userfiles/file/nekazizuli.pdfIn PDF document text
    • http://www.impactit.in/ckfinder/userfiles/files/potiguvananuwedemorimoke.pdfIn PDF document text
    • https://ruxthai-guesthouse-chiangmai.com/ckfinder/userfiles/files/89927612176.pdfIn PDF document text
    • http://dbcasagayathottam.org/assets/uploads/cms_images/files/nakemadusul.pdfIn PDF document text
    • http://cambresisemploi.fr/ckfinder/userfiles/files/98720267406.pdfIn PDF document text
    • http://drukarnia-skawina.pl/app/webroot/media/files/53735456472.pdfIn PDF document text
    • https://resttour.com/images/userfiles/files/zubonuzerumij.pdfIn PDF document text
    • https://baxsporthorses.com/userfiles/file/91424398380.pdfIn PDF document text
    • https://sieuviet.net/webroot/img/files/rimujokojid.pdfIn PDF document text
    • http://www.siphonicflowmandiri.com/upload/files/xalogokoru.pdfIn PDF document text
    • https://ecoolteh.eu/galeria/file/25930026112.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=notes+of+ch+1+indian+economy+class+12PDF 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_off0000b040.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB040 14840 bytes
SHA-256: ed3b2789f96f561fe1620a9b3dbba5c895d4667378a3511bdcb4b0641ec4ace1
font_01_sfnt_off0000d4da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD4DA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ecf1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECF1 10904 bytes
SHA-256: 06d233bd80b25f4a6a69f34e3911782d7dbcc7d9494cba798736c06249b19c82