Malicious PDF — malware analysis report

Static analysis result for SHA-256 903c3261445a855d…

MALICIOUS

PDF

84.3 KB Created: 2021-09-18 14:46:24 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: ca8980383facb8fe7b21bc178cd3bdaa SHA-1: 2853618860dd22114fbe9797d786c9cedae5df5a SHA-256: 903c3261445a855deadaf208ec6eda00feb0736fab2c47ed7ef1c9418ca6607f
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to distribute malicious content. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware delivery through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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 http://jysfh.com/upload_fck/file/2021-9-7/20210907034605889575.pdf In PDF document text
    • https://huuphongplastic.vn/uploads/images/files/jilowugake.pdfIn PDF document text
    • http://engroupe.ca/aym_image/files/51771426714.pdfIn PDF document text
    • http://oio.cn/uploadfiles/files/sejetikoguwubaw.pdfIn PDF document text
    • http://guojingmall.com/userfiles/file///80452665625.pdfIn PDF document text
    • https://seerupit.dk/assens/file/xafufepixejesigunexomesej.pdfIn PDF document text
    • https://christembassybarking.org/wp-content/plugins/super-forms/uploads/php/files/89b05a6d42d9f3cf9ae69f7da8235d4e/36390209669.pdfIn PDF document text
    • http://csc021.com/userfiles/file/20210918180612_zhnpz1.pdfIn PDF document text
    • https://value.ae/userfiles/file/kanenadasapeladapadufuro.pdfIn PDF document text
    • http://aygroupmuh.com/image/files/30221598152.pdfIn PDF document text
    • http://grandfiltr.com/files/file/kamikerularekifojiba.pdfIn PDF document text
    • https://malmospelmanslag.se/userfiles/file/47684209314.pdfIn PDF document text
    • http://thietbimaugiao.vn/Images_upload/files/38162143050.pdfIn PDF document text
    • https://cubic.is/userfiles/file/lutozujebobud.pdfIn PDF document text
    • http://machulski.com/public/file/74047922812.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134f95ec93d1---8617099329.pdfIn PDF document text
    • http://vetcasatenovo.it/userfiles/files/16264151138.pdfIn PDF document text
    • https://penzion-palice.cz/content/xifegofixadixinekimabafug.pdfIn PDF document text
    • https://givemeit.ru/wp-content/plugins/super-forms/uploads/php/files/598aa59383fb77ab8f466783fb3469b1/mizudajomo.pdfIn PDF document text
    • http://bisenzia.it/userfiles/files/96997195267.pdfIn PDF document text
    • http://chapelguild.com/images/usr/98429281624.pdfIn PDF document text
    • http://jawarakreasi.com/file/36808983474.pdfIn PDF document text
    • https://tresonance.org/uploadfiles/vifepapovuresaj.pdfIn PDF document text
    • http://ranaghatpchsschool.org/userfiles/file/46501877372.pdfIn PDF document text
    • http://yksskj.com/ckfinder/userfiles/files/nuvelevofa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=how+do+i+change+my+greeting+on+my+android+phonePDF 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_off0000e34e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE34E 18408 bytes
SHA-256: 368967174fd4187917c3953924de6796ae55d5bb90ddabdf7d5ac43d0c41513a
font_01_sfnt_off0001132f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1132F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012b46.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12B46 10940 bytes
SHA-256: 9419ddb202303288dd59678a88565e4a2ec985c7f2928b22ecfcc473f8bd556b