Malicious PDF — malware analysis report

Static analysis result for SHA-256 6a03c8b2df23faa1…

MALICIOUS

PDF

90.2 KB Created: 2021-08-11 21:51:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 25c3ef63ffe889f6ecf74cb99a30b332 SHA-1: 5ac114056696ef1c34b2f54efef0adc8d94c337d SHA-256: 6a03c8b2df23faa105338b56fffcabb541ae565e6e3fec895ed261dd664f23f1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs that point to PDF files hosted on various domains, some of which appear to be compromised CMS uploads. The presence of a link farm suggests an attempt to manipulate search engine results or distribute further malicious content, aligning with phishing and SEO poisoning tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://chupanhnoithat.vn/upload/files/44461788997.pdf In PDF document text
    • https://groupunsur1.com/contents//files/6223279099.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607153c15cf5c---34819269321.pdfIn PDF document text
    • https://www.skyline-recruiting.com/wp-content/plugins/super-forms/uploads/php/files/394ab5a31f8769789e503ee7490599bc/9480828927.pdfIn PDF document text
    • https://baruipur.org/ckfinder/userfiles/files/98330042345.pdfIn PDF document text
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/16073bee20ec9c---61996173627.pdfIn PDF document text
    • https://binarbaidservices.com/public_html/userfiles/file/xeminaxev.pdfIn PDF document text
    • https://mbzl-pro.xyz/web/img/podborky/files/diparom.pdfIn PDF document text
    • https://dennismaloney.ca/upload/editor/file/55462781404.pdfIn PDF document text
    • http://diamondsnspurs.com/clients/12200/File/zixolubawifaxiba.pdfIn PDF document text
    • http://xn----9sbkvfu2aex3d.xn--p1ai/ckfinder/userfiles/files/47121327826.pdfIn PDF document text
    • http://pericosrentcar.com.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160fda33f453ff---pulotubodusazu.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160a3625431698---sajonenuwiguridid.pdfIn PDF document text
    • http://fisioterapiasuzzara.it/userfiles/files/vasukivefekufegufarad.pdfIn PDF document text
    • http://detikakdeti.ru/img/file/kakiwuvabuvidi.pdfIn PDF document text
    • http://brianhaymore.com/images/e/file/67172786291.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d9dae9be71---leloxelivajetom.pdfIn PDF document text
    • http://phamtrangia.com/upload/files/6837747694.pdfIn PDF document text
    • http://andlupa.com/userfiles/file/kisibawubikajanafer.pdfIn PDF document text
    • http://www.gametimecatering.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b077e5a6bfc---93275452413.pdfIn PDF document text
    • http://cariboohose.com/userfiles/file/nodeji.pdfIn PDF document text
    • https://atolab.it/wp-content/plugins/super-forms/uploads/php/files/6d4b7ae3e4fa20f42f85d64e3a7c4f42/21825029484.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=teenage+mutant+ninja+turtles+1987+season+4+episode+15PDF 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_off0000f955.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF955 17332 bytes
SHA-256: 8cae8e31c1c028daf69e8b75a948dc74ec0c954a8965cf095492dab0fa7529fe
font_01_sfnt_off0001266d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1266D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013e84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13E84 11620 bytes
SHA-256: 2f6aef6e170838f7ea1b00e073060ace97c91127a2300284afb6bfba5753deae