Malicious PDF — malware analysis report

Static analysis result for SHA-256 b7110a0f452e5eee…

MALICIOUS

PDF

82.0 KB Created: 2021-03-16 06:11:34 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: c46b48469cda8d59432d73d3123e778d SHA-1: b6c72587e43a2e4aab9ffed130c8b394276823ef SHA-256: b7110a0f452e5eee1e2e7543feb808bc38d3a5306ac413868982476e1c6c48d7
196 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including PDF_SEO_LINK_FARM and PDF_SUSPICIOUS_LINK_LURE, indicating it contains numerous links to potentially harmful external sites. The ML classifier and ClamAV also identified it as malicious. The embedded URLs, such as http://securitycheckingbrowservkcom.xyz/39678694221nxtcd.pdf, suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9954

Heuristics 6

  • 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
  • Image-heavy PDF with invisible link to suspicious domain high PDF_SUSPICIOUS_LINK_LURE
    PDF is a small image-heavy lure with invisible link annotations that send the user to a suspicious high-risk-domain URI. This matches credential-phishing carriers where the visible document is only a prompt and the real collection flow happens on the linked website.
  • 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://jacksth.ru/award?keyword=algebra+worksheets+for+7th+grade+pdf
    • https://cdn-cms.f-static.net/uploads/4501054/normal_5fdaf34fcc2a7.pdf
    • https://cdn-cms.f-static.net/uploads/4455174/normal_5fd9aad79b240.pdf
    • https://cdn-cms.f-static.net/uploads/4486742/normal_603daabec78b2.pdf
    • https://cdn-cms.f-static.net/uploads/4482618/normal_5fd144ee9533e.pdf
    • http://securitycheckingbrowservkcom.xyz/39678694221nxtcd.pdf
    • https://migawireradafus.weebly.com/uploads/1/3/2/6/132695569/535ac102c5b.pdf
    • https://cdn-cms.f-static.net/uploads/4505839/normal_5fd7882f08e27.pdf
    • https://static.s123-cdn-static.com/uploads/4485440/normal_5fc7029796ffc.pdf
    • https://static.s123-cdn-static.com/uploads/4369305/normal_5ff77287727be.pdf
    • https://static.s123-cdn-static.com/uploads/4386081/normal_5fcd46b58a86b.pdf
    • https://jabenawonidibe.weebly.com/uploads/1/3/5/3/135385032/xelenakavutaxeb.pdf
    • https://cdn-cms.f-static.net/uploads/4471704/normal_603792b39c8fd.pdf
    • https://jodakinikap.weebly.com/uploads/1/3/4/3/134375895/sevoz.pdf
    • http://study-english-05.site/when_was_the_dell_latitude_e6540_madeei2uo.pdf
    • https://static.s123-cdn-static.com/uploads/4384026/normal_5ff84affbd2a2.pdf
    • https://static.s123-cdn-static.com/uploads/4450340/normal_5ffb8f70c455b.pdf
    • http://smartcoin.design/how_to_get_level_1_crossfit_certificationve2p8.pdf
    • https://cdn-cms.f-static.net/uploads/4393364/normal_5fd6a2366bbaf.pdf
    • http://tersq.fun/midnight_sun_tanning_near_mervegy.pdf
    • https://losewilim.weebly.com/uploads/1/3/4/8/134854933/bemusurusoxim.pdf
    • https://dezijetide.weebly.com/uploads/1/3/4/8/134864221/f664b06ee0a99f9.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://uploads.strikinglycdn.com/files/f00cfb3c-e6ff-4e83-8a5e-e1fcea0b42e3/6924136663.pdf
    • https://uploads.strikinglycdn.com/files/bed7e94d-3288-45df-8f32-99a8f7e07e71/flowers_for_algernon_quotes_miss_kinnian.pdf
    • https://uploads.strikinglycdn.com/files/8022d863-5150-468c-b936-01f42ed88516/sat_answer_booklet.pdf
    • https://uploads.strikinglycdn.com/files/a1494089-077f-4341-82b1-bc18eabb7a77/rabinovivafirigipanoleju.pdf
    • https://uploads.strikinglycdn.com/files/27a891df-42d1-485e-9611-414d13b4fc1b/bram_stokers_dracula_characters.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f5c8.bin
d79fd651bcf92b43c994d672ba9af7822f4a73f61224c133f88ba65bf174e659
pdf-font-stream PDF embedded font (sfnt) at offset 0xF5C8 5300 bytes
font_01_sfnt_off000107fc.bin
5a00edcdf9937f3cdb54189f7b05769244c03b9dea4496e18ad5c9d801164af2
pdf-font-stream PDF embedded font (sfnt) at offset 0x107FC 10508 bytes
font_02_sfnt_off00012bd1.bin
d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378
pdf-font-stream PDF embedded font (sfnt) at offset 0x12BD1 4324 bytes