Malicious PDF — malware analysis report

Static analysis result for SHA-256 39481ee56fed7314…

MALICIOUS

PDF

80.6 KB Created: 2021-05-20 18:26:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-20
MD5: 9987b13b029c0bc1709e2c83ad64805e SHA-1: a3ea32b784a3e2eefd99860ebf53f09c71093050 SHA-256: 39481ee56fed7314102611ee53266403bcb2e2d998356a328da046648b5db282
156 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many of which are generated for SEO purposes, indicating a link farm or spam campaign. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and numerous external links point towards an attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 5

  • 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.
  • 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://seumenha.ru/strik?utm_term=asvab+word+knowledge+practice+test+2019 PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4413346/normal_5febef57eceef.pdfIn PDF document text
    • https://labomozojaxige.weebly.com/uploads/1/3/0/7/130738499/0fb793c1b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393022/normal_605d23276699b.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4495241/normal_605c0bd6609c3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4503787/normal_600db0e7a2759.pdfIn PDF document text
    • https://soxajerufoxizas.weebly.com/uploads/1/3/4/8/134880654/6d9df37e6314.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4445743/normal_606bc2a44f5ee.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4459477/normal_6001904c3bdb6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369506/normal_605e0d84873f4.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4495694/normal_6008dd92639d7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4413983/normal_5fdc0c26b79d8.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4417221/normal_6018344e3f04d.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4375352/normal_5ff4f27f2272f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4371244/normal_60407fb148586.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4469827/normal_603c8122c6a56.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470962/normal_605f712922897.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4497369/normal_601b34d8ed198.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/0b2d90a8-f5bd-4122-927d-097e66bfb82c/37322910823.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/484604ca-2168-44c8-9d48-2a6fc88dafef/mercury_25_hp_4_stroke_service_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e27496a7-2721-4de0-9d53-c4edc2b8ebed/how_to_setup_jabra_wireless_headset.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3fddbf20-97db-49d9-8319-eac5251f5bcd/data_science_and_analytics_course_in_bangalore.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9bd124ef-c6e2-4181-83fe-053cb86acfc9/krishna_ji_ke_bhajan_video_mein_badhiya_badhiya.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3004a9bb-9582-44ab-a7a2-36498131bf77/memory_trace_definition_psychology.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d4b127dd-d218-4412-926f-16913191a06b/what_to_ask_in_couples_counseling.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/05b179bf-7b37-4a44-95c5-d8c3cc6bb095/harga_mixer_yamaha_16_ch.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/aeb55553-3f81-4197-9876-4ecbe2b5dd5a/comcast_remote_control_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/95b97c76-78d2-4443-9905-7df18822469a/how_to_program_time_warner_remote_to_vizio_tv.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_off0000fb19.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB19 6068 bytes
SHA-256: 509e88ec2be6972f295175c932e4f67f984b6ef091a445528c5dcf65e30d651a
font_01_sfnt_off00010fe8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FE8 10732 bytes
SHA-256: 3fccf24754b87f82fa62ebe1d60fb711af483d6b9b649ebaec0435f6e1169056