Malicious PDF — malware analysis report

Static analysis result for SHA-256 d3fb310050c7d724…

MALICIOUS

PDF

74.6 KB Created: 2021-09-19 20:32:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: d5d50e311428fd7a2d952d0234154372 SHA-1: 5f3ca90d0ac18f84a362c565e9f56b238e71aed1 SHA-256: d3fb310050c7d724c09d0dd8c11991219b75ed5ca56c4739adaf80a34f7dd42d
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to compromised websites or disposable domains, indicative of a link farm designed to redirect users to malicious content. ClamAV detected this file as Pdf.Phishing.Trojan, and the ML classifier also flagged it as malicious. The presence of multiple external URIs and link farm heuristics strongly suggests a phishing or malware distribution attempt.

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 https://inwebjor.ru/uplcv?utm_term=usb+debugging+how+to+enable PDF link annotation
    • https://alev.az/userfiles/file/fixip.pdfIn PDF document text
    • https://autohausnschmidt.de/userfiles/file/27176406256.pdfIn PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613b076ba0911---69517798882.pdfIn PDF document text
    • http://bantinnhadat.com/users/files/tenerirudekikabam.pdfIn PDF document text
    • http://hondasushi.com/uploads/files/sedijuzazamixutaxomidux.pdfIn PDF document text
    • http://v-lukomorie.com/uploader/files/13704129778.pdfIn PDF document text
    • http://miskolciharsona.hu/pictures/file/84740154347.pdfIn PDF document text
    • https://mlbcsimleague.com/ckfinder/userfiles/files/83746221795.pdfIn PDF document text
    • https://www.truesdalepainting.com/wp-content/plugins/formcraft/file-upload/server/content/files/161306fb4a7896---59260336420.pdfIn PDF document text
    • https://hoatuoi360.vn/uploads/files/senibiso.pdfIn PDF document text
    • http://status-go.net/gfx/userfiles/files/75372529574.pdfIn PDF document text
    • http://chaodontuonglai.vn/uploads/ck_upload/files/66119580208.pdfIn PDF document text
    • https://buka.ru/sadm_files/ruzulagiwewovamefige.pdfIn PDF document text
    • http://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/53146438919.pdfIn PDF document text
    • https://www.sgestrecho.es/wp-content/plugins/formcraft/file-upload/server/content/files/161371dc354345---gepesesa.pdfIn PDF document text
    • https://inprovituruguay.com/ckfinder/userfiles/files/12129120635.pdfIn PDF document text
    • http://dnepropress.net/files/file/dudamokumagebe.pdfIn PDF document text
    • http://studiotecnicodama.it/userfiles/files/31340881704.pdfIn PDF document text
    • https://kocarbonag.com/luutru/files/zosotema.pdfIn PDF document text
    • http://dr-onesrl.com/userfiles/files/tipexefez.pdfIn PDF document text
    • http://conflictfreeelectronics.com/ourprojects/chowki/UserFiles/renuka/file/mezokugokedupadevi.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_off0000c215.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC215 16476 bytes
SHA-256: c503f439344f93d2757f7610e18306dfcaf5ab32bb51eed6c2e4607412fe1126
font_01_sfnt_off0000ec96.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC96 10760 bytes
SHA-256: d025057835b448c8c1b5a03da5146117fecad24c868d5eba7fee9a636ec04f34
font_02_sfnt_off00010517.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10517 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1