Malicious PDF — malware analysis report

Static analysis result for SHA-256 9f3cceb79dd1247f…

MALICIOUS

PDF

74.4 KB Created: 2021-09-19 00:12:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 83de2b043b8c8e277fee0efc269a2cb1 SHA-1: 79217ce171edda28e7ed7b353e90822d9fba0ace SHA-256: 9f3cceb79dd1247f52be345fdb18de8e5158dec54c2bafd3e2fc6d14f7b026bd
156 Risk Score

Malware Insights

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

The file was detected as a malicious PDF by ClamAV and an ML classifier. Static analysis revealed it functions as a link farm, with numerous URLs pointing to potentially compromised websites or disposable hosting. The presence of multiple PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics indicates a deliberate attempt to obscure the final destination and leverage compromised infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://dreamwith.gni.kr/ckupload/files/zitojuk.pdf In PDF document text
    • https://408of53crownstreet.com/assets/media/files/74321436745.pdfIn PDF document text
    • http://architettotoma.it/userfiles/files/38403484650.pdfIn PDF document text
    • http://signauction.net/userfiles/file/lupexiguxibipexubovojat.pdfIn PDF document text
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613104343e029---turamela.pdfIn PDF document text
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613277cf38cca---63337883214.pdfIn PDF document text
    • http://atreve.eu/ubezpiecz/obrazy/file/denaromofakixis.pdfIn PDF document text
    • https://blsautomation.com/ckfinder/userfiles/files/metemav.pdfIn PDF document text
    • http://leap-egypt.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143880943e94---32096243661.pdfIn PDF document text
    • https://portecitadelle.portecitadelle.ca/ckfinder/userfiles/files/mizupiwuwawime.pdfIn PDF document text
    • https://eastoncn.housemember.com/uploads/files/87347230452.pdfIn PDF document text
    • http://importfoodfair.com/userfiles/image/2021/09/file/61961016451.pdfIn PDF document text
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141a41f689e1---tikoketesagovesijodigib.pdfIn PDF document text
    • http://tuvanluatdanang.com/upload/ck/files/xezapomuzisuxatawix.pdfIn PDF document text
    • http://mariautonoleggiomarsala.it/userfiles/files/tubiziwoju.pdfIn PDF document text
    • http://ownlines.com/upfiles/file/getone.pdfIn PDF document text
    • https://confidence-ist.com/ckfinder/userfiles/files/wefazifalud.pdfIn PDF document text
    • http://fiumevivo.it/userfiles/files/zosul.pdfIn PDF document text
    • https://swotin.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137b151a515b---bumokewixutuvamisud.pdfIn PDF document text
    • http://www.scsk12.org/policy/files/files/19437592584.pdfIn PDF document text
    • http://averon.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613c203519398---64406992449.pdfIn PDF document text
    • http://positiveforce.in/uploads/files/sikugimofarapikigoxozo.pdfIn PDF document text
    • http://atel-j.nl/uploads/files/10399706967.pdfIn PDF document text
    • http://irollee.com/userfiles/file/rodiv.pdfIn PDF document text
    • http://abnicum.com/files/file/81585012969.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=super+monkey+2+mod+apkPDF 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_off0000c0a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC0A0 16632 bytes
SHA-256: 24092603774d34778e8fbb7846656e184aca70cdf63794c1cb7bcebe8405032e
font_01_sfnt_off0000eb55.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB55 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001036c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1036C 10648 bytes
SHA-256: 6ea1a90ccbd8ccb28f605803fcd8e947264be629c674303913f10a2932aa4027