Malicious PDF — malware analysis report

Static analysis result for SHA-256 f3cf7b123eb2d3b9…

MALICIOUS

PDF

80.3 KB Created: 2021-03-25 01:19:15 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: a7c729e107e263e14c7cb31ebbf24299 SHA-1: 342885e51327129639e580afcc96d17f68aa1b8e SHA-256: f3cf7b123eb2d3b94505a7dc9d4c5199027598703ba356d262f23aff493dbcd5
254 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

The PDF contains numerous embedded links designed to direct users to external websites, including a known malicious redirector at 'https://yafferge.ru/strik?utm_term=social+psychology+myers+pdf+free'. This indicates a phishing or scam attempt disguised as a free download. The ML classifier and ClamAV detection strongly support its malicious nature, likely exploiting PDF vulnerabilities to redirect users.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://yafferge.ru/strik?utm_term=social+psychology+myers+pdf+free In PDF document text
    • https://static.s123-cdn-static.com/uploads/4369643/normal_60020ccbba756.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4428045/normal_5fdf2a269ceb7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383572/normal_60309c67b314a.pdfIn PDF document text
    • http://supobesopo.mygamesonline.org/mugoginizasu.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4499942/normal_5fcb486a074ef.pdfIn PDF document text
    • http://avtoshkola-region26.ru/oster_digital_toaster_oven_manualdi5mj.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4445103/normal_5fc571b0d6801.pdfIn PDF document text
    • http://libopadu.scienceontheweb.net/angularjs_tutorialspoint_download.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4425214/normal_604d01285edb7.pdfIn PDF document text
    • http://xelasurugopu.mywebcommunity.org/dedirelodejuvanugamer.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4476566/normal_6028f88c048d6.pdfIn PDF document text
    • http://obzorov.site/obusforme_mattress_warrantye3i3u.pdfIn PDF document text
    • http://biotringel.shop/45384214932eyk8k.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4415944/normal_5fcc16e988f82.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/6a3f13eb-65d4-4935-942d-78fb7085107c/bakukilijokelanasawejukuz.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9638564a-8293-4e23-b49a-ad9e4b755939/90630313639.pdfIn PDF document text
    • https://0dd0cd87-80d3-4eb5-b9c6-73c43c3a6fca.filesusr.com/ugd/f0b6b3_f8bf64c82aef452eb9638039d67e8654.pdf?index=trueIn PDF document text
    • https://7ae52be2-ba3c-41fb-8935-29281088223e.filesusr.com/ugd/affaa6_9bfc5c253db84d0fa1ad0a581bedeb0d.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/dc542249-e9bb-4764-b59d-7af727df1aff/lenovizefufav.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/59363398-ff26-4ad2-92a2-c760d40f4a30/vintage_polaroid_sun_600_lms_instant_camera.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_off0000fbd4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBD4 5776 bytes
SHA-256: 854e0874179d311c762e77fd7d02ede0f423d1355af116392d6ea90732ae6c3f
font_01_sfnt_off00010f5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F5D 10700 bytes
SHA-256: 172062352e544792cc6cfb9cfcb51cb8a9b2c984019f068727a40f1ad4936d87