Malicious PDF — malware analysis report

Static analysis result for SHA-256 1f1651e1f02453d1…

MALICIOUS

PDF

86.6 KB Created: 2021-06-09 05:36:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: b43499bcdf676f68a5e25600000637fa SHA-1: 3c6c3d8040d4240ca734cce0c7b2e9bc9e5f975c SHA-256: 1f1651e1f02453d1b54d37da68b6c8d4fdb3594d0aba404a1ca7d141e14e0231
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many hosted on disposable domains, suggesting a link farm designed to obscure the final malicious destination. The heuristic 'PDF_SEO_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly indicate this malicious intent. ClamAV detection as 'Pdf.Phishing.Trojan' further supports the malicious classification. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the link farm suggest a phishing or redirection attack.

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
  • 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.
  • 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://krisoc.ru/pbw?utm_term=michael+aaron+piano+course+pdf+free+download PDF link annotation
    • https://simefaburiso.weebly.com/uploads/1/3/0/8/130814859/67ce3d8b22.pdfIn PDF document text
    • https://wazexusevawixi.weebly.com/uploads/1/3/0/7/130776334/sozel.pdfIn PDF document text
    • https://sukojafura.weebly.com/uploads/1/3/4/6/134632918/7479d20e.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4461791/normal_5fcfb42cd8637.pdfIn PDF document text
    • https://xajimago.weebly.com/uploads/1/3/0/8/130813364/naxomefawojum-rasos-kepamibige.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4391335/normal_600be854c9df3.pdfIn PDF document text
    • https://mudekireziwafa.weebly.com/uploads/1/3/4/7/134730614/19843a74dc7ad4.pdfIn PDF document text
    • https://dawokopo.weebly.com/uploads/1/3/5/3/135314789/3876135.pdfIn PDF document text
    • https://figiroxofidun.weebly.com/uploads/1/3/0/7/130740151/garezenesuwope.pdfIn PDF document text
    • https://kojaxinepizoju.weebly.com/uploads/1/3/1/8/131856409/zagipirujol-pumepolapesi-junazaguxezo.pdfIn PDF document text
    • https://fizozedodid.weebly.com/uploads/1/3/4/4/134484686/tubunuku-miwitifulofepof.pdfIn PDF document text
    • https://kaxapajitab.weebly.com/uploads/1/3/4/8/134896246/3d9a3ae5465.pdfIn PDF document text
    • https://pofofeteb.weebly.com/uploads/1/3/2/6/132681268/rosuwatotus.pdfIn PDF document text
    • https://sepafolelobonel.weebly.com/uploads/1/3/4/6/134614676/vateduxupo_pisutunupabuge_xamokuzip_jopafunizowe.pdfIn PDF document text
    • https://zikivunebek.weebly.com/uploads/1/3/5/9/135964247/fopemix.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4380230/normal_60b5b41ee214b.pdfIn PDF document text
    • https://sadejakudabad.weebly.com/uploads/1/3/5/9/135965210/xetoxi.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4480408/normal_606436a4ac71c.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/4401111e-a206-418d-9a28-22c579c71e15/dafizabupitopemorefaje.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/29f4f707-095f-4971-a80f-a0ee1b3566f4/audiveris_the_open_source_to_musicxml_converter.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5ed2fd40-4f87-465b-8a1c-d34e58e7987b/white_christmas_lyrics_michael_buble_shania.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_off000112b5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x112B5 5340 bytes
SHA-256: 683eaf3dac41ed86e8768c7983b3415f6185b71e1598929d5457fbe571f777f3
font_01_sfnt_off000124f6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x124F6 11596 bytes
SHA-256: a13ddabc171cbed9aa1e11db5805041c96e0056ee402a31328b5189eae246cbb