Malicious PDF — malware analysis report

Static analysis result for SHA-256 f87db16481d10bcc…

MALICIOUS

PDF

73.7 KB Created: 2021-09-16 11:50:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: f5ea51376716a4d3aa138c2f0b56ad61 SHA-1: 0cce8e1c25066014ac2c9374eef17b5dc9f9c695 SHA-256: f87db16481d10bcc2ad0f9001bacc7a212790505561d8f08eabecc310f0aa7b8
156 Risk Score

Malware Insights

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

The file was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. Static analysis revealed it functions as a link farm, containing numerous URLs pointing to various websites. Several of these URLs are hosted on compromised CMS upload directories or disposable domains, indicating a likely attempt to lure users to malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://h04ydivan.ru/userfiles/file/mewinafinewositir.pdf In PDF document text
    • http://futurepoolandspa.com/ckfinder/userfiles/files/lesavibijewobazadiv.pdfIn PDF document text
    • http://szilasfood.hu/pic_upload/files/rabatosibazipivunixazajen.pdfIn PDF document text
    • https://amzentransportationindustries.com/admin/imagetemp1/file/35411677241.pdfIn PDF document text
    • https://vietnamwelder.vn/uploads/news_file/bexemisuzolanufuxanududem.pdfIn PDF document text
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133da1776b58---jeramaxekapem.pdfIn PDF document text
    • https://refundsrefunds.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f5da0ae58c---mosirajinapazuro.pdfIn PDF document text
    • http://xn----8sbaqfskngn1qi.xn--p1ai/userfiles/file/kutanewewepagoxajafe.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b6c95e15e9---dubezofinojexajerulo.pdfIn PDF document text
    • http://flirtproducties.nl/ckfinder/userfiles/files/85841224752.pdfIn PDF document text
    • http://www.movingintofreedom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fdca9934f6---lubowok.pdfIn PDF document text
    • https://salwangurugram.com/files/pawupinin.pdfIn PDF document text
    • http://contrast.no/ckfinder/userfiles/files/78326689562.pdfIn PDF document text
    • https://kingwaterpure.com/ckfinder/userfiles/files/56892378416.pdfIn PDF document text
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16141f21aa9b11---tobeterawefa.pdfIn PDF document text
    • https://polandpools.com/contents/files/nawajenuzozamuzubexuw.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16140bdea02a00---30610918622.pdfIn PDF document text
    • https://commonlawhouse.in/userfiles/file/zigazizopaposama.pdfIn PDF document text
    • http://aktifimmo.lu/userfiles/files/debuvo.pdfIn PDF document text
    • http://elma1.ru/!upload/files/kujewuxiga.pdfIn PDF document text
    • https://christianklein.eu/Quansis/ckfinder/userfiles/files/nidevowagizuparalez.pdfIn PDF document text
    • https://happycondo.leaddeehub.com/userfiles/files/losemeposolodexipefi.pdfIn PDF document text
    • http://blackhorsesc.pl/userfiles/file/zutaluwovima.pdfIn PDF document text
    • http://julianina.de/upload/file/kuroxofagivuvirerapemurob.pdfIn PDF document text
    • http://eperon-kochersberg.com/img_db/22310926387.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=cloudcat+premium+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_off0000bb87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB87 17500 bytes
SHA-256: 8c91aa5f37d61726c88ed03614350ccf8899e06d3b12e81d3c3ff84466c3bc42
font_01_sfnt_off0000e8d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8D7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000100ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100EE 10628 bytes
SHA-256: 503ba2addda9ec39122e14d0be59ac83ac0029a31a63351f84c235d4a1986e59