Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8b3747b071571c4…

MALICIOUS

PDF

87.7 KB Created: 2021-08-20 06:17:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 8b75cead7602bd9d70fe68a1e725fc17 SHA-1: 55e877b2a355a080fb0f8fb89bb6cca77ca44810 SHA-256: b8b3747b071571c4f1adfc29fa4e75198f157dec104f55f3dcfdd07ccc3efe88
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. It contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The document body is heavily obfuscated and unreadable, providing no direct clues to its specific purpose beyond the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://slenderclub.cz/ckfinder/userfiles/files/60932202813.pdf In PDF document text
    • http://www.expo-hotel.com/english/wp-content/plugins/formcraft/file-upload/server/content/files/1608719a02304e---gakenobig.pdfIn PDF document text
    • http://akvatoria.by/UserFiles/files/dukub.pdfIn PDF document text
    • http://www.gametimecatering.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607185b4a5924---60911795974.pdfIn PDF document text
    • https://twr1115.net/files/fckeditor/file/sufogofenu.pdfIn PDF document text
    • http://library.nesdb.go.th/ic/admin/ckfinder/userfiles/files/fevipabakaxaj.pdfIn PDF document text
    • https://telenovella-bg.com/files/32008280774.pdfIn PDF document text
    • http://greenbiotech.vn/uploads/userfiles/file/48713232219.pdfIn PDF document text
    • https://soalmatematik.com/userfiles/file/pofeva.pdfIn PDF document text
    • https://nikolsbeauty.com/webroot/f/uploads/file/28557282161.pdfIn PDF document text
    • https://chambres-hotes-aube-bleue.fr/userfiles/file/5827070577.pdfIn PDF document text
    • http://greece-ex.com/togevodamidikalabotinozim.pdfIn PDF document text
    • https://berbagiangka.com/contents//files/18383471463.pdfIn PDF document text
    • http://currycornersugarland.com/admin/images/file/runepixisozavupi.pdfIn PDF document text
    • https://fleschimmo.lu/userfiles/files/saropozegalezivu.pdfIn PDF document text
    • http://www.thebetterinsurance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160931475cb5bd---92663326679.pdfIn PDF document text
    • https://tlpnw.com/wp-content/plugins/super-forms/uploads/php/files/b424c7d54895eea5217946abd10f8ee3/sigojanedumuluteraz.pdfIn PDF document text
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c3971703825---40275158063.pdfIn PDF document text
    • http://morgancountyoh.com/userimages/nifedex.pdfIn PDF document text
    • http://biurod9.pl/public/userfiles/file/29966465198.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=how+to+measure+bowling+speed+in+mobile+appPDF link annotation
    • http://lovewhereyoulv.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/cbb0df20b006381b87a753030113f6ba/gagokimezemelowosukagog.pdfIn PDF document text
    • 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_off0000f294.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF294 11052 bytes
SHA-256: 32cbca42f55920662505ae30c9cd60a8e42a4cfb9d526917305152923d383467
font_01_sfnt_off00010bdf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BDF 17224 bytes
SHA-256: 2b5b4931c4b44a378100012eca0eafc8ed4dd522ccaddf0d34aae778c22a8b9a
font_02_sfnt_off0001390a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1390A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1