Malicious PDF — malware analysis report

Static analysis result for SHA-256 81187daf22e2bad5…

MALICIOUS

PDF

68.7 KB Created: 2021-10-03 03:37:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 7abaf361be42861c5a1b2c09848b5b84 SHA-1: acdfdf00d02e7410f475375f90a153bb18838400 SHA-256: 81187daf22e2bad5996b34a1e90c0965add642ebba4553dc615bcc5ca8a89a78
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It functions as a link farm, with numerous URLs pointing to compromised WordPress sites and disposable hosting, likely to obscure the ultimate destination. The presence of multiple PDF link farm heuristics indicates a deliberate attempt to distribute links to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9950

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://camile.vn/wp-content/plugins/super-forms/uploads/php/files/eemacslnf19vh80v9cl0a69r34/kusasubitirowuvi.pdf In PDF document text
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/cbvpv6ou4r1gr0aa2756mnm6cd/sifipafupe.pdfIn PDF document text
    • https://holcom-wd.com/webroot/img/files/15351270606.pdfIn PDF document text
    • https://lesura.net/userfiles/file/71797194966.pdfIn PDF document text
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16156172bbdbde---90479244895.pdfIn PDF document text
    • http://qhchemicalsfeed.com/upload/files/62326719717.pdfIn PDF document text
    • http://dostavkaturov.ru/files/file/19437781300.pdfIn PDF document text
    • https://obrbikes.com/files/files/92958049778.pdfIn PDF document text
    • http://emrc.ie/upload/imagecontent/file/tojidegevinirixujivekub.pdfIn PDF document text
    • https://12shio2.com/contents/files/99767743354.pdfIn PDF document text
    • http://nationshield.ae/userfiles/files/sanozekevefekivuwu.pdfIn PDF document text
    • https://aldea.work/wp-content/plugins/super-forms/uploads/php/files/1f03865b667fb2c89d6071e17ede5408/35443794140.pdfIn PDF document text
    • http://abwcockeysville.com/uploads/files/tirofewejozilid.pdfIn PDF document text
    • https://nepalihemp.com/ckfinder/userfiles/files/juvobuwi.pdfIn PDF document text
    • http://s-privod.ru/userfiles/file/44829015648.pdfIn PDF document text
    • https://ppsu.cz/files/file/nabaworax.pdfIn PDF document text
    • http://minhtoangalaxyhotel.vn/app/webroot/files/ckfinder/files/pefudeloraritoror.pdfIn PDF document text
    • http://oikoscoccatoarchitettura.com/userfiles/files/96120025486.pdfIn PDF document text
    • http://gptools.net/userfiles/file/34451167851.pdfIn PDF document text
    • https://ecpa.fr/uploaded/file/53183700857.pdfIn PDF document text
    • http://gazomotor.com/allinone/file/rasimef.pdfIn PDF document text
    • http://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/16147158f0d1ba---xejekusumadidaxuz.pdfIn PDF document text
    • http://dar-tom.pl/userfiles/file/71654249084.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/jiwakejaf.pdfIn PDF document text
    • http://jjmcp.jp/userfiles/Image/file/tujife.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=easy+welsh+rarebit+without+beerPDF 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_off0000b055.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB055 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c86c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC86C 10524 bytes
SHA-256: f1ad8939ae56d19ca3078911a44eb9388d5f212c1153ab4ad8017612125ad0dc
font_02_sfnt_off0000e09a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE09A 14628 bytes
SHA-256: 5e9245337fb38b9100f7ad594988d98ba0d736a87b7412386fa877ee4fca5bab