Malicious PDF — malware analysis report

Static analysis result for SHA-256 ff6bcdcfc3527fa7…

MALICIOUS

PDF

72.4 KB Created: 2021-04-05 13:37:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 61af7f7ea906844ebcb5a62d725c6e09 SHA-1: 9507ac8a38586d90d4fed6fa22185288b95aadcc SHA-256: ff6bcdcfc3527fa7c9d2932240b0f816425bfd55d701fed83eaf1d2f5e1b19f3
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 numeric slugs, indicating a link farm designed to manipulate search engine results. One prominent URL, 'https://soxebez.ru/wix?keyword=genetics+test+study+guide+answers', is presented as a lure for study guide answers. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 5

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://soxebez.ru/wix?keyword=genetics+test+study+guide+answers
    • https://cdn.sqhk.co/wuzufoxo/5S7hdif/mexaredofasapajedusezi.pdf
    • https://kutumamam.weebly.com/uploads/1/3/4/8/134893394/kilivasef.pdf
    • https://mufuwavujove.weebly.com/uploads/1/3/4/0/134042856/fc775fc7.pdf
    • https://jepejopik.weebly.com/uploads/1/3/4/6/134610321/95be00295.pdf
    • https://cdn.sqhk.co/kivipemo/yUjhOie/kidafodalatariforinoporeb.pdf
    • https://cdn.sqhk.co/zuvomafoda/hgeZLWG/cute_backgrounds_for_computer.pdf
    • https://lijipowurop.weebly.com/uploads/1/3/4/3/134314174/1e9e7d0451abe.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/41881df0-0e46-4f5d-84bd-c26e410d32a6/51837713639.pdf
    • https://54957a25-093b-4cbd-a4f0-8eb5fea931f0.filesusr.com/ugd/8ba634_6cb3ca7a251747029692cc57e1a9ee38.pdf?index=true
    • https://s3.amazonaws.com/satuja/how_to_make_money_in_stocks_4th_edition.pdf
    • https://s3.amazonaws.com/sobaketemu/cecotec_3490_manual.pdf
    • https://uploads.strikinglycdn.com/files/27d6dc66-d85e-4a1e-916e-c5f4d7564979/69898965241.pdf
    • https://s3.amazonaws.com/xazarujokemus/bjcp_score_sheet.pdf
    • https://1c92f6d8-19eb-429c-9239-1cf6be91372f.filesusr.com/ugd/cc1a03_42e7cb5a05fe478398c74f1f2a6dd719.pdf?index=true
    • https://uploads.strikinglycdn.com/files/f2495987-f1cf-49de-b8c5-c59e0f11b473/can_alkaline_diet_help_acid_reflux.pdf
    • https://189c2d36-84ff-4b81-9465-96c33c1d3b91.filesusr.com/ugd/35ddae_1975b0ef9937451b96de5769644598c5.pdf?index=true
    • https://s3.amazonaws.com/xotomisen/binopapifekigenerutun.pdf
    • https://uploads.strikinglycdn.com/files/ccb5fcda-df13-4e91-9377-0f78a394bcfc/tech_drawing_app_for_mac.pdf
    • https://uploads.strikinglycdn.com/files/42e67e37-38b3-4465-984f-cab964418e2c/how_to_calculate_interest_on_loan_in_tally.pdf
    • https://uploads.strikinglycdn.com/files/e287b75b-60f6-492d-ae0f-5767a1a9c0cf/places_you_can_get_free_food_for_good_grades.pdf
    • https://uploads.strikinglycdn.com/files/b0a56c95-b084-46f0-b98a-52e016983502/sosobimeb.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dd73.bin
e34c930aa08ea9c18de0e4a56bab200503fc3c7df91d9b426e1a23946bb95d38
pdf-font-stream PDF embedded font (sfnt) at offset 0xDD73 5300 bytes
font_01_sfnt_off0000efa5.bin
92eb99156fa2328e880deb69b6841eb9009be1e64df9f9df8c4b02ae92bb14e2
pdf-font-stream PDF embedded font (sfnt) at offset 0xEFA5 10780 bytes