Malicious PDF — malware analysis report

Static analysis result for SHA-256 81f0c3cc94de02e6…

MALICIOUS

PDF

87.3 KB Created: 2021-06-27 10:03:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 67a76b7b68ec0f2794097594ec1e2352 SHA-1: 3803ab474499f31e722b8d43582135dcabbcf8ef SHA-256: 81f0c3cc94de02e6890b881865c0dc6fa84c71d0002cf96bbd640ae130a585c0
156 Risk Score

Malware Insights

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

The PDF file was identified as malicious by ClamAV and an ML classifier. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites. These sites likely serve as a distribution point for further malicious content or phishing attempts, indicated by the 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM' heuristics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9835

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://go-trec.com/wp-content/plugins/super-forms/uploads/php/files/86kos6po2ljh0nntgrm5ts01j6/32601520987.pdf In PDF document text
    • http://pocatellocampfire.com/wp-content/plugins/super-forms/uploads/php/files/6mifh7m9hmuk03dd4fktlo9o4j/wisegepametulurosi.pdfIn PDF document text
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/gsnaocp040vc1ve1q8v1sn8n03/93607036197.pdfIn PDF document text
    • https://www.finestkindcharter.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089bb3fb1f5d---58410858970.pdfIn PDF document text
    • https://him-home.ru/wp-content/plugins/super-forms/uploads/php/files/a9decfe42407d428f5ddeba31df52365/27409127331.pdfIn PDF document text
    • http://houselandia.ru/files/jipix.pdfIn PDF document text
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c2c543851f1---meponubiwemulalisimid.pdfIn PDF document text
    • http://www.mediacomriccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/160d43839300fc---varugavutuxar.pdfIn PDF document text
    • http://pechati-piter.ru/userfiles/file/10983067976.pdfIn PDF document text
    • http://metzpaintings.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bac1ed19b84---xumexoso.pdfIn PDF document text
    • https://www.certificagreen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a28d951b83---mubadevugoduva.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/160728a3e4d20f---gepiwepawu.pdfIn PDF document text
    • http://cageart.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160a43aa1b2868---forilematuputofe.pdfIn PDF document text
    • http://princeworldwide.com/multimedia/userfiles/file/77703308051.pdfIn PDF document text
    • http://nousgarage.com/userfiles/file/15827654338.pdfIn PDF document text
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/160a22e365abbf---52031669602.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b0026252e10---gavijudo.pdfIn PDF document text
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091a250becbf---72563201208.pdfIn PDF document text
    • https://scavilecis.it/userfiles/file/46162865799.pdfIn PDF document text
    • https://la-klamm.org/userfiles/file/luguw.pdfIn PDF document text
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/adaa6et9intd6tluhucg3sufeo/vasekimujikoloja.pdfIn PDF document text
    • https://callalilyvn.com/upload/files/wukazapirivifozizejakewi.pdfIn PDF document text
    • https://drainscovers.com/wp-content/plugins/super-forms/uploads/php/files/16b5ece91593d373f9b77b52bda33263/buxagibemomolidupotogo.pdfIn PDF document text
    • https://maugli24.ru/wp-content/plugins/super-forms/uploads/php/files/25197fbb9e48d09610c7f2eeefafa1ac/65334157681.pdfIn PDF document text
    • http://1-cx.com/ckfinder/userfiles/files/7299364713.pdfIn PDF document text
    • http://attep.com/home/sandbox/domains/heekee.com.hk/public_html/ckfinder/userfiles/files/dowibirapanideguba.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=2021+ford+mustang+fastbackPDF 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_off0000f2a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2A0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010ab2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AB2 16656 bytes
SHA-256: ba83b6e1b743452a2b128fdd7e3163c70dbcdb8f16d48bfa47a5555c2781e29e
font_02_sfnt_off0001364b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1364B 11076 bytes
SHA-256: 7e628392ff4466d9e487021745e2679a5c25b50e45147a2996b274396b9ae24b