Malicious PDF — malware analysis report

Static analysis result for SHA-256 15c773373d4b66df…

MALICIOUS

PDF

74.5 KB Created: 2021-09-19 02:06:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 411d9ea7ca44456ecfb1338c64b222c4 SHA-1: e1325d48f876dd40b95b543c0af4109947807938 SHA-256: 15c773373d4b66df7f7db8772b67d3924850874e596148c47ccaecde5fff6110
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of external URI heuristics and link farm indicators further supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://gaia-onlus.org/userfiles/file/60206733000.pdf In PDF document text
    • http://baocaosudanang24h.com/uploads/image/files/39430652399.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613d8f52dc073---dujunupupuzumor.pdfIn PDF document text
    • https://study-abroad-travel.com/ckfinder/userfiles/file/25098351240.pdfIn PDF document text
    • http://topbondtape.com/uploadss/file/91234599498.pdfIn PDF document text
    • http://ktcyy.com/ckfinder/userfiles/files/falamifosarudizewi.pdfIn PDF document text
    • http://matrixuniverzum.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1613c30ae8c3e2---xalesofilonevibukudo.pdfIn PDF document text
    • https://owop.challengersports.com/userfiles/files/37619201016.pdfIn PDF document text
    • http://ebslang.net/_UploadFile/Images/file/wefeguf.pdfIn PDF document text
    • https://bandai-k.com/userfiles/file/tekavozikikokewikolim.pdfIn PDF document text
    • http://newcityhk.com/userfiles/fixerolosu.pdfIn PDF document text
    • http://jcbcharpentebois.com/ressource/site-image/files/ditararakuto.pdfIn PDF document text
    • https://bf-pomosch.ru/wp-content/plugins/super-forms/uploads/php/files/mi0rqevln6mpme7bbdf3219i35/kazexosepilojit.pdfIn PDF document text
    • http://eotp.info/sites/default/files/fck/file/83792226924.pdfIn PDF document text
    • http://teplorium.su/userfiles/file/sozikebademipalutuviker.pdfIn PDF document text
    • http://gdlianyu.com/uploadfiles/file/13355025668.pdfIn PDF document text
    • https://pasifikendustriyel.com/userfiles/file/wovonok.pdfIn PDF document text
    • https://sunsoftinfoway.net/ckfinder/userfiles/files/lipukosiv.pdfIn PDF document text
    • http://school15-tyumen.ru/f/94725241465.pdfIn PDF document text
    • https://landlorddebtadvisory.com/wp-content/plugins/super-forms/uploads/php/files/669454e568000d815aa5bc37d3c848da/48271181271.pdfIn PDF document text
    • https://poojaindiangrill.com/nbloom/fckuploads/file/vasewarakeduxek.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/GLLx1DTH0VQ/uplcv?utm_term=nouns+exercises+pdfPDF 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_off0000bffd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBFFD 17164 bytes
SHA-256: 4777247bd768e8769480a61c7339a72fbcf4d29165b88b2b289dd6791774deec
font_01_sfnt_off0000eca9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xECA9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000104c0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104C0 10484 bytes
SHA-256: edad2b035f90c68ffbf0eaa662ff1a6e3049b41bfec1313145b14e68ddc3a686