Malicious PDF — malware analysis report

Static analysis result for SHA-256 8aa2f6d16bab276f…

MALICIOUS

PDF

85.3 KB Created: 2021-09-15 19:22:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: ded900753361ae44432bfeabb3325f00 SHA-1: fc2c79b700d1eafed5be1c93a7a3305a3b5df083 SHA-256: 8aa2f6d16bab276f2d9fd5f0655b0c5678761a62275b2f0e8032ba1294e251a3
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS upload storage and disposable domains. The embedded URLs and the nature of the link farm suggest a phishing or SEO manipulation scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://krisoc.ru/uplcv?utm_term=how+to+get+instagram+free+likes PDF link annotation
    • http://j1ent.com/userfiles/file/20210910050121.pdfIn PDF document text
    • https://kligi.viart.lt/ckfinder/userfiles/files/15778995296.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16138752abf4c0---51582757820.pdfIn PDF document text
    • https://xosobacninh.vn/webroot/img/files/veboraxijowarefilabo.pdfIn PDF document text
    • https://karapinler.com/calisma2/files/uploads/4353699046.pdfIn PDF document text
    • http://futimisdev.com/userfiles/file/gonosuzi.pdfIn PDF document text
    • https://it-remarketing.pl/app/webroot/media/files/zurikonebidefefiwufitupe.pdfIn PDF document text
    • http://jsushibrea.com/uploads/files/77356189858.pdfIn PDF document text
    • http://splhardware.com/UploadFile/file/2021090401013473499.pdfIn PDF document text
    • http://www.rpv-drachten.nl/files/file/8548116939.pdfIn PDF document text
    • http://kazenergy.kz/wp-content/plugins/formcraft/file-upload/server/content/files/1613f58781067d---zezevonopezafivegefupeni.pdfIn PDF document text
    • http://meadescafe.com/userfiles/file/95690899162.pdfIn PDF document text
    • http://dnt-mayak.ru/content/File/70298598814.pdfIn PDF document text
    • https://probidjp.com/ckfinder/userfiles/files/20210913_231132.pdfIn PDF document text
    • http://hwayoung.kr/upfile/files/98954331743.pdfIn PDF document text
    • http://czernavendeghaz.hu/admin1/file/xaxakipolozanax.pdfIn PDF document text
    • https://westcoastmovers.ca/wp-content/plugins/super-forms/uploads/php/files/j79lumalnrmjrukfupvij31j2f/kudaturegedewuw.pdfIn PDF document text
    • https://postele-z-masivu.sk/ckfinder/userfiles/files/durugarugesir.pdfIn PDF document text
    • http://angarakshaksecurity.com/userfiles/file/54476498955.pdfIn PDF document text
    • http://ccsilver.kr/files/fckeditor/file/160982340961419ff6d18b5.pdfIn PDF document text
    • http://zopos.zohukum.com/ckfinder/userfiles/files/38458140251.pdfIn PDF document text
    • http://www.golfusa.be/userfiles/files/xezasipabewijonex.pdfIn PDF document text
    • http://smolninskayahotel.com/userfiles/file/32639894615.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_off0000e82f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE82F 18416 bytes
SHA-256: f4d71e594092c3ea609c0f6acf426f562c33d31a0887f157c42dac05cb6cf5b8
font_01_sfnt_off000116dd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x116DD 10724 bytes
SHA-256: 28708d230ce5554ebe81e9e7717bc51fc86c0ff18f865c972402b44a64b0a7ad
font_02_sfnt_off00012f89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12F89 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1