Malicious PDF — malware analysis report

Static analysis result for SHA-256 559fd581da30cbc7…

MALICIOUS

PDF

78.1 KB Created: 2021-06-19 22:11:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: 6a643df6b417fa03faf2699d37c83c6f SHA-1: 18b9c4cc1325a9585a3eed000e6b15947f4fb001 SHA-256: 559fd581da30cbc7458494522b9983429873b5fdc8419c52c9dc6cbef93530c3
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate the document functions as a link farm, directing users to multiple compromised or disposable hosting sites. The presence of numerous PDF links and the use of compromised CMS upload storage suggest an attempt to distribute malicious content or conduct phishing attacks.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://camberwelltaxi.com/survey/userfiles/files/movudukutapikinom.pdf In PDF document text
    • https://otdelkamos.ru/wp-content/plugins/super-forms/uploads/php/files/2615bee5a4065706f3e9f33185568c22/famevak.pdfIn PDF document text
    • http://beulahcooleycollection.com/clients/870349/File/78910358943.pdfIn PDF document text
    • https://n-v-v.dk/userfiles/file/75489630457.pdfIn PDF document text
    • https://ecobox.eng.br/wp-content/plugins/super-forms/uploads/php/files/gbn9q68hrtliebc612s13o3p48/60465688477.pdfIn PDF document text
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/6620392df78c493588a0676cb9ce4fcb/tofufilowugiwekafuf.pdfIn PDF document text
    • http://drentmedischadvies.nl/uploads/files/45639171868.pdfIn PDF document text
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/a2dbab89d4b4d0ec9337720dba98ca64/72793549450.pdfIn PDF document text
    • http://www.victorian-manor.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1608dcdc203bf7---68312373997.pdfIn PDF document text
    • https://www.cfo-search.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a8f32eb2ca0---tisafavijowod.pdfIn PDF document text
    • http://amtusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607231d1586b7---6059773166.pdfIn PDF document text
    • http://englandmatchshirts.com/assets/file/sudofitobivuvasukomelu.pdfIn PDF document text
    • http://drsuthichai.com/userfiles/files/70482280420.pdfIn PDF document text
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1609c6f5bbe84c---28936717669.pdfIn PDF document text
    • http://rlangkhan.com/upload/userfiles/files/mitiwexijixasumoxiwike.pdfIn PDF document text
    • http://deltastal.ru/userfiles/file/22515576976.pdfIn PDF document text
    • https://www.ringtonex.com/mp3/2020/crazy-frog.mp3In PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=crazy+frog+tonePDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e651.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE651 4640 bytes
SHA-256: 5ac366f7a70bc90f4186da20bb19ccf37144041c629aefac20e12f5f30b310aa
font_01_sfnt_off0000f637.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF637 11588 bytes
SHA-256: 5d81337a2de75238a10edf3e00056848b844d409ea8f1a6d2290a204ae1602fb
font_02_sfnt_off00011dbf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DBF 4324 bytes
SHA-256: a542ec26cea93e049a2e27cd59b1347dd9bbdea13775fd7b822b3c2b3136116f