Malicious PDF — malware analysis report

Static analysis result for SHA-256 797950e90158eb92…

MALICIOUS

PDF

83.1 KB Created: 2021-09-14 10:17:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ceb5a7708961564a91c8f071533c0c8e SHA-1: 685871e301f3a766456bcbc9759487bd758a1a95 SHA-256: 797950e90158eb921982d98b4257bb9fb6b7bde116d874a2e0930f91b14ce3e5
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected by ClamAV as a Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous links to compromised CMS uploads and disposable hosting, suggesting it acts as a link farm to redirect users to malicious sites. The PDF structure itself is also noted as potentially compromised, with duplicate object bodies.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 https://tahuacoop.com/cms_gpadmin2015/sgi_userfiles/userfiles/files/venusowitusofosijojenob.pdf
    • http://keifo.ru/ckfinder/userfiles/files/80627673424.pdf
    • http://www.fotografoeventimilano.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bdb7a54225---25539673053.pdf
    • http://okfilm.kr/userData/board/file/pepita.pdf
    • http://irodaszer.lukinserv.hu/file/tuwisodirof.pdf
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c07673b4ce---8785464430.pdf
    • http://hide-bo.com/img/tmp/file/34336296294.pdf
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1612feb743d080---wefiditasewinuzitan.pdf
    • http://arucax.am/user_images/file/faximalofikemezunarebum.pdf
    • http://inruho.ru/ckfinder/userfiles/files/zopalepemex.pdf
    • http://officeharbor.com/pdtInfo/18877264705.pdf
    • http://3sdent.com/upload/files/larebanujiduzidose.pdf
    • https://nguyenvanhuongloc.vn/app/webroot/files/images/pages/files/39824062083.pdf
    • https://ruta.hu/ckfinder/userfiles/files/zuzizatuxoj.pdf
    • http://cityfate.com/files/files/72548115647.pdf
    • https://pet-fashion.ro/mm/file/tipijasojukiwafotomonuma.pdf
    • http://321eastern-thailand.com/userfiles/files/54268362307.pdf
    • http://bluestandard.pl/ckfinder/userfiles/files/32367978857.pdf
    • https://www.cocochan.com.pk/wp-content/plugins/super-forms/uploads/php/files/5a53be88d66d745855b8d00be7e4d6c0/kukus.pdf
    • http://xn--9w3b270a7kf.kr/data/editor/file/85056581828.pdf
    • https://marbeyoyun.com/calisma2/files/uploads/66580084357.pdf
    • https://j26clean.com/upload/files/xisokagipipededar.pdf
    • http://kondicionery-domodedovo.ru/upload_picture/file/garejamanemuwowunodi.pdf
    • https://asthasupermarket.com/userfiles/file/53550399888.pdf
    • http://simsvizag.com/admin/uploadedfiles/file///60223946174.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=ldplayer+lol+wild+rift
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000df82.bin
19883efc6400cf56d292fa8bf445bab6435a8c4fd6e5417eef9eeafaa5bccc02
pdf-font-stream PDF embedded font (sfnt) at offset 0xDF82 18064 bytes
font_01_sfnt_off00010de3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x10DE3 16792 bytes
font_02_sfnt_off000125fa.bin
8dde1d41bd66e2e5648dd476e50ef488bee38ada8f57d3cccb22d462916b9481
pdf-font-stream PDF embedded font (sfnt) at offset 0x125FA 10376 bytes