Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8d981d45a53d4bb…

MALICIOUS

PDF

92.1 KB Created: 2021-08-08 19:09:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 9b996cc7881488b360dd911fce6beee9 SHA-1: b643f17d6ddcfb200acecc7f1c3ac3a3cca25100 SHA-256: a8d981d45a53d4bb6e7e64f3f94eaaa57aab24f1f6e1fda91eb3e2a8e1071f91
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to compromised WordPress upload directories, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The embedded URLs and the PDF structure are consistent with a malicious document designed to lure users to external, potentially harmful, sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9913

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://suhrsmad.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160b0988b09050---37123451601.pdf In PDF document text
    • http://africanhairbraidingsalon.com/userfiles/file/68410857177.pdfIn PDF document text
    • http://babamoleskine.com/files/file/lejaviwekifarisitifilu.pdfIn PDF document text
    • https://www.nestroots.com/wp-content/plugins/super-forms/uploads/php/files/48obp82rertat58h0809s76na4/bavobubiwu.pdfIn PDF document text
    • http://intergeored.com/upload/File/vukiw.pdfIn PDF document text
    • http://xn--80aaeiengkwpz6p.xn--p1ai/pub/file/wofarunujibiwolofesa.pdfIn PDF document text
    • http://agiusfuneraldirectors.com/files/file/90690633643.pdfIn PDF document text
    • http://www.elsecretodelolivo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dfc3d94fda3---vekiwemizesumifutetenu.pdfIn PDF document text
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/16095f0cbc5c60---96661191324.pdfIn PDF document text
    • https://abe-rdc.com/userfiles/file/vokedawofagavogusovalom.pdfIn PDF document text
    • http://papianiarch.it/userfiles/files/julis.pdfIn PDF document text
    • http://clinivetmadonnadirosa.eu/userfiles/files/kiximu.pdfIn PDF document text
    • https://kompaspt1.com/contents//files/69846121403.pdfIn PDF document text
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/160905ebd1f819---vixodudomugasofovigopep.pdfIn PDF document text
    • http://project-st.ru/userfiles/file/vijejupunibut.pdfIn PDF document text
    • https://www.citysecurity.org.uk/wp-content/plugins/super-forms/uploads/php/files/8vqcs3sasr8hihtu72hcbd0ffo/43596022545.pdfIn PDF document text
    • http://sarahscupcakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fd103ec1ff8---medidika.pdfIn PDF document text
    • https://gearforfree.com/wp-content/plugins/super-forms/uploads/php/files/1slpensbsmqag17i1mm6nqu0q6/81088933917.pdfIn PDF document text
    • https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160e8ef0b58267---gezomafulisonale.pdfIn PDF document text
    • http://eros-arena-reutlingen.de/eros/userfiles/file/nolupu.pdfIn PDF document text
    • http://dtpokebar.com/uploads/files/45386682735.pdfIn PDF document text
    • http://glassco.ca/clients/9/99/99aa1728c1dafa3cf8773a75727b87c9/File/kikutemorivikutuvojan.pdfIn PDF document text
    • https://aradmissions.com/ci/userfiles/files/30792153731.pdfIn PDF document text
    • http://ziguratex.com/helpdesk/app/webroot/img/userfiles/files/46747050783.pdfIn PDF document text
    • https://dbmotorbrokers.com/userfiles/file/banogavonabomulepamokal.pdfIn PDF document text
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/82aa30a16a1f05313861585e824a0a22/67635091314.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/YTWXjIUwRh0/uplcv?utm_term=what+did+the+rev+die+ofPDF 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_off0001057e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1057E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011d90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D90 17672 bytes
SHA-256: 3b91987e7cfbf559d9e08b936bd6e12fbd331750e7d7e958bdd892f276f6f265
font_02_sfnt_off00014be2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14BE2 10192 bytes
SHA-256: 0000e90765c3cf3c8a932ef1623a7fa2217a69a6efbbabe5032014fd880cc36b