Malicious PDF — malware analysis report

Static analysis result for SHA-256 73bc5f857b0798d9…

MALICIOUS

PDF

76.6 KB Created: 2021-05-28 06:41:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: c976fa7b95790498db3d0bbacea97cc0 SHA-1: 2969c46d992c24091fab96d2f9160ec5b0b2420c SHA-256: 73bc5f857b0798d99dbcebef81ec261e76ca0090161c9a88fdd64fd48d016db9
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 to PDF files, suggesting a link farm or SEO spamming tactic. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution. The embedded URLs point to suspicious domains, and the document's content is obfuscated, preventing a clear understanding of its specific payload but indicating a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://nipisod.ru/strik?utm_term=borderline+personality+disorder+worksheets+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4422147/normal_5fdb3d500626a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4468540/normal_6029c309a3101.pdfIn PDF document text
    • https://mikutefax.weebly.com/uploads/1/3/4/8/134866710/7626032.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4371814/normal_6029054ecda6d.pdfIn PDF document text
    • https://sipedevesebin.weebly.com/uploads/1/3/4/8/134879103/mepijob-vetagamiwimum.pdfIn PDF document text
    • https://pukokisawar.weebly.com/uploads/1/3/4/7/134749025/3770732.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4374366/normal_605c3a6e92014.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/6f857976-610f-4994-959b-6a338f81c597/tome_of_beasts_2_online_free.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/88b869a2-3bff-4af9-9487-29d22f9c2e92/93057308848.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5f2980bf-2edd-4c7f-9a08-a20fe082af06/3rd_grade_reading_comprehension_common_core.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b01bbe4d-56d5-47db-9c95-bf6e33165601/858632772.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b47ff230-54ac-4ed4-8c8d-8394104a8e5b/what_are_some_disadvantages_of_mobile_technology.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/97919051-f470-4671-98b3-d8810883b603/90386087435.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/410c82b4-927b-474b-98fa-ebed5aefb4bc/how_to_use_blue_jeans_video_conferencing.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/63eebaff-88fa-4412-82a8-c5d850a9c045/what_jobs_can_a_reading_specialist_do.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d6427a83-1e56-4023-aa93-9a0d4388d0c2/como_se_cura_la_ansiedad_nerviosa_naturalmente.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/c0c360a0-7bb1-4f0a-b947-01227ef37538/practical_electronics_for_inventors_fourth_edition_review.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8db9fae1-f3c4-4826-81d4-870032571805/9868653440.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a1de2da8-0a3f-47be-8b51-2299a1efad1d/wagner_flexio_590_paint_sprayer_troubleshooting.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/70b0ceb7-98b9-492c-ae6e-417cf76e2c65/64508846410.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/98dbe89b-3eaa-422c-a03e-232cc53a0fe8/farodufajizawozedisuzez.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_off0000ebef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEBEF 5436 bytes
SHA-256: c204e068d3d585f341d542083b5e40a01a0da3f519caa034f0c1215092a70cd3
font_01_sfnt_off0000fe7e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFE7E 11212 bytes
SHA-256: d7adf3b0b9d30874ad6d51f30b28a162616be1288fb04788c838249b221c254f