Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9bc87f94c206081…

MALICIOUS

PDF

79.0 KB Created: 2021-08-20 19:18:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 36e8185574199569d91eb25cf0bbbfdb SHA-1: 04b219b2c44773da5e2ddff0b7ef90201385a62e SHA-256: b9bc87f94c2060817f1ea015ae43ea2ad68497e7adc1e183fed56f811ec18360
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as a phishing trojan and ML classifiers indicated a high probability of maliciousness. The heuristics identified it as a link farm, with many URLs pointing to compromised CMS uploads and disposable hosting. The document body is unreadable, but the presence of numerous external links suggests an attempt to redirect the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://stsaischoolamritsar.com/slbdavbatala/userfiles/file/boguzijoxu.pdf In PDF document text
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/16090f9ba4649c---26322665264.pdfIn PDF document text
    • http://webscape.co.bw/wp-content/plugins/formcraft/file-upload/server/content/files/160bf5417589a0---ditogopu.pdfIn PDF document text
    • http://sung1.com/upload/files/33787440285.pdfIn PDF document text
    • http://hani-bee.com/userfiles/files/45549596314.pdfIn PDF document text
    • http://bamt.be/wp-content/plugins/formcraft/file-upload/server/content/files/16079bcf00d0c1---18092558822.pdfIn PDF document text
    • http://www.anieliasfx.com/uploads/textareas/file/2926827237.pdfIn PDF document text
    • http://abwjefferson.com/uploads/files/84608036551.pdfIn PDF document text
    • http://www.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/5g397oci6nmam1a5c2g83kv1i3/jizanox.pdfIn PDF document text
    • http://milcontabil.com.br/wp-content/plugins/super-forms/uploads/php/files/ciu3cl3ifh2re7l9poqqak7fo4/gavulubevaxokidewogewu.pdfIn PDF document text
    • https://christianboudreau.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b48e94c0ea4---tovirotulo.pdfIn PDF document text
    • http://euro-ex.com/11265123434.pdfIn PDF document text
    • https://dursunguney.com/userfiles/files/zuloxedidufapa.pdfIn PDF document text
    • http://matstravel.ru/userfiles/file/74942387322.pdfIn PDF document text
    • http://divorce-difficile.fr/userfiles/file/35384165701.pdfIn PDF document text
    • https://www.reachcast.ca/wp-content/plugins/super-forms/uploads/php/files/d3fb989111191c87a0e3093c9547156e/sazibabozupara.pdfIn PDF document text
    • http://yuha.be/_files/file/60245078374.pdfIn PDF document text
    • http://aaaexpressheating.com/userfiles/file/sevig.pdfIn PDF document text
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/16094e5450ee9c---797731105.pdfIn PDF document text
    • https://ifacemount.com/wp-content/plugins/super-forms/uploads/php/files/bs7cc8ntumktv9cjobf7ae673o/85727329101.pdfIn PDF document text
    • https://reflexlighting.com/wp-content/plugins/super-forms/uploads/php/files/01c80405df98014bf0172ce2878ba86e/41932995405.pdfIn PDF document text
    • http://permanentnimakeup-brno.cz/userfiles/files/puzawo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=sand+balls+mod+apk+1.+1.+40PDF 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_off0000d359.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD359 10756 bytes
SHA-256: df5280558adc640d6f8c0996b085ad95951d0c698f545eec22018f5656ebce33
font_01_sfnt_off0000ebda.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBDA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000103ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103EC 16920 bytes
SHA-256: fd791c541a03a9c32160351a3926b46b1eae8a1cd4204d869d24d237821b7861