Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b8503fcd0b1771d…

MALICIOUS

PDF

83.8 KB Created: 2021-09-04 21:18:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 0713fcc897e079d9898a2852b1d418fb SHA-1: ad5e84645142558baf056e689c7bfe4451ed65ac SHA-256: 3b8503fcd0b1771d5c872181509a2e9c3a554da19b9c5bf8ad9b1a684e19e166
156 Risk Score

Malware Insights

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

The PDF contains numerous links, many pointing to compromised WordPress upload directories, suggesting a link farm designed to redirect users to malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. No scripts were extracted, so the primary attack vector appears to be the embedded links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9938

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 https://dtcprojects.com.au/wp-content/plugins/super-forms/uploads/php/files/rlqbksvt8aenl6slep9h18olah/zunafan.pdf In PDF document text
    • http://transbur.ru/admin/ckfinder/userfiles/files/funefajovapubirosapal.pdfIn PDF document text
    • https://prikolnaya.com/wp-content/plugins/super-forms/uploads/php/files/0e62ee724229b83d6939057125bd4cd7/gekuduxatavutinusilikek.pdfIn PDF document text
    • http://www.veronicaneal.com/wp-content/plugins/formcraft/file-upload/server/content/files/1/1608ce633636db---tevebodonilesap.pdfIn PDF document text
    • http://www.leasebridge.com/CKUPimg/files/gagesatabokezutelagato.pdfIn PDF document text
    • http://hyosangjo.com/userfiles/file/20210829162929.pdfIn PDF document text
    • https://maggievanostrand.com/uploads/media/file/30949160965.pdfIn PDF document text
    • http://www.frank-diagn.hu/userfiles/files/66671575633.pdfIn PDF document text
    • http://studiotecnicoprato.eu/userfiles/files/menawaguzuzafuja.pdfIn PDF document text
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608027ce6196d---gadubuzira.pdfIn PDF document text
    • http://ahlhy.com/uploads/file/020234352368.pdfIn PDF document text
    • http://cuatudongsaigon.net/uploads/files/17741614550.pdfIn PDF document text
    • https://ekransamara.ru/files/93378085911.pdfIn PDF document text
    • http://trans-serwis.com/userfiles/file/kosusixu.pdfIn PDF document text
    • http://www.greenbriarpropmgmt.com/wp-content/plugins/super-forms/uploads/php/files/aef723a70e408efe3d5497d0ab302c70/laziri.pdfIn PDF document text
    • https://ibrahimkoc.com/images/Media/files/waxajutevivogino.pdfIn PDF document text
    • http://www.sensible-seeds-premium.com/wp-content/plugins/formcraft/file-upload/server/content/files/160becd6cc8acf---23047570515.pdfIn PDF document text
    • http://domplus.su/userfiles/files/likozisotitorew.pdfIn PDF document text
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081eac1b5990---fimupedimezozifesebuzivib.pdfIn PDF document text
    • https://njsolarpower.com/wp-content/plugins/super-forms/uploads/php/files/6c0b2d45364d847c4c31a38ced4e9b8b/80412611277.pdfIn PDF document text
    • https://laneopx.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bcc3e94a29b---90650949225.pdfIn PDF document text
    • https://www.foundationofhope.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607e299613f4c---75329497137.pdfIn PDF document text
    • https://hagepoorter.be/files/files/sakadesesizamixalipij.pdfIn PDF document text
    • https://www.financedeclined.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1608e8b2769be0---25121208747.pdfIn PDF document text
    • http://for-rent-aalst.com/wp-content/plugins/formcraft/file-upload/server/content/files/160777124dfa25---figuwuduxoku.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=trolley+manual+jackPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cb83.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB83 17480 bytes
SHA-256: ce3173821b67d9ca85498ed0ad6ffb3d78e0729250775e0d8b9110b2072459a7
font_01_sfnt_off0000e611.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE611 10432 bytes
SHA-256: 793b222ee088a634fca9548179636e3852800068409e3c056c5845146e171919
font_02_sfnt_off0000fdb9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDB9 16644 bytes
SHA-256: 734dd0498c4fdf72e826785465bd7b2d4c94a8013dbe5f66b786cd12ccf4d134
font_03_sfnt_off0001291d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1291D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1