Malicious PDF — malware analysis report

Static analysis result for SHA-256 91bfe71db1e39d44…

MALICIOUS

PDF

75.6 KB Created: 2021-06-14 00:27:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-13
MD5: 552e2e548ce3a2a2b6aaf05e2edf8790 SHA-1: ce24ec2685b530df1f97efbdc82bf2ba3d7ef28d SHA-256: 91bfe71db1e39d44820ffa121221629136fa9464b5be323d43d1beb23f7a2dcc
244 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains a large number of links to external websites, many of which are hosted on disposable domains and appear to be part of a link farm. One critical heuristic indicates a link to known malicious redirector infrastructure. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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.
  • 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://dafemum.ru/123?utm_term=background+check+android+pie In PDF document text
    • https://cdn-cms.f-static.net/uploads/4368955/normal_6019485a5e278.pdfIn PDF document text
    • https://ketafimevudo.weebly.com/uploads/1/3/1/6/131637081/kizuk_wopavegupowad_wosugam_bixosaxat.pdfIn PDF document text
    • https://sepuzemafunud.weebly.com/uploads/1/3/4/5/134584668/5878047.pdfIn PDF document text
    • https://lekorasosin.weebly.com/uploads/1/3/4/6/134612915/d2e074d39e9.pdfIn PDF document text
    • https://fofawuparojimi.weebly.com/uploads/1/3/1/0/131070926/730184b57a24e.pdfIn PDF document text
    • https://tujiwukof.weebly.com/uploads/1/3/4/5/134592642/1557634.pdfIn PDF document text
    • https://fozixaxo.weebly.com/uploads/1/3/4/6/134665632/fdd5e.pdfIn PDF document text
    • https://jerolota.weebly.com/uploads/1/3/4/8/134859034/vapilesomivifo.pdfIn PDF document text
    • https://fadunununi.weebly.com/uploads/1/3/4/7/134747036/1515506.pdfIn PDF document text
    • https://silorofolukut.weebly.com/uploads/1/3/4/2/134265947/rovulaw_xulofegisexamon_fupave_bodapuwiwobidi.pdfIn PDF document text
    • https://valezofijamope.weebly.com/uploads/1/3/4/4/134445284/4388664.pdfIn PDF document text
    • https://wujezevo.weebly.com/uploads/1/3/0/8/130874127/1f45d49f53.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4495399/normal_5fec55575dfe6.pdfIn PDF document text
    • https://metumarexidema.weebly.com/uploads/1/3/4/5/134591821/vofapebokidaxaganox.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/15341ec5-fe7e-4b58-8b04-40c7750b7e8d/xizetuzifusukowewojimima.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4a6f67a8-474a-4f01-b190-aca57696cbe0/puxezele.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c6902346-1e83-4fbf-8cda-fdb9cf51a156/vofaxaxuredot.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9a78595d-43fd-4363-99d3-d8ae996f8e1c/kung_fu_training_book.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/def5933c-afc0-4390-b862-c9926b02c656/juzudapavuwekaxipo.pdfIn PDF document text
    • http://figuduvimeti.pbworks.com/f/65329170446.pdfIn PDF document text
    • http://daladefadus.pbworks.com/f/pendulum_dowsing_charts_book.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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000eb33.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB33 5240 bytes
SHA-256: adb09659e77fb434458d3c35633a9c5d86b13aea6cb1bfa8c9424977bda65cfc
font_01_sfnt_off0000fd05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD05 10656 bytes
SHA-256: 3fa959df7483759e8c896b8bd4edf955379ce7a06478b90a16b4ffb2a3d12786