Malicious PDF — malware analysis report

Static analysis result for SHA-256 7a851d4ac32c3636…

MALICIOUS

PDF

84.1 KB Created: 2021-03-18 00:34:40 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-20
MD5: 06fa0d93720db641ee1a7b337840f14b SHA-1: 849b7c4571ed149306cc62e61ae0e6767b0681b1 SHA-256: 7a851d4ac32c36369e0dc4d75a3bc7f0d63ea4a8c765240b029ab77fe48b3560
186 Risk Score

Malware Insights

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

The PDF file contains numerous external links, many hosted on disposable domains, suggesting a link farm or SEO spam operation. The document body, though heavily obfuscated, appears to be a lure for an 'admission guide'. The presence of PDF_SEO_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM heuristics, along with ClamAV detection as Pdf.Phishing.Trojan, strongly indicates malicious intent. No scripts were extracted, but the PDF structure itself facilitates the redirection to malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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
  • 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.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://fokemale.ru/123?utm_term=admission+guide+book+for+diploma+2019%252F+20 PDF link annotation
    • https://guladusive.weebly.com/uploads/1/3/0/9/130969442/koduniribezi-nunexukiverolat-kunuzoj.pdfIn PDF document text
    • https://cdn.sqhk.co/fofateze/hjjbOhf/snow_white_evil_queen_costume.pdfIn PDF document text
    • https://cdn.sqhk.co/bulixanejad/mjaHrp5/40166828695.pdfIn PDF document text
    • https://cdn.sqhk.co/dilizilozok/jjW60ji/22477628610.pdfIn PDF document text
    • https://cdn.sqhk.co/sevijeruba/hhgiDji/xupowijidedunokime.pdfIn PDF document text
    • http://5coupon.info/fusiwumodosigabopilubial2u4.pdfIn PDF document text
    • http://brumbum2.xyz/37340030864pr8ir.pdfIn PDF document text
    • https://cdn.sqhk.co/melobokodijo/fJujdgf/fekovitiji.pdfIn PDF document text
    • http://intekzafast.online/dotudekca5pr.pdfIn PDF document text
    • https://cdn.sqhk.co/setewefasari/dhijgKW/realm_grinder_guide_r10.pdfIn PDF document text
    • https://cdn.sqhk.co/fekoguwiwu/XFgdDON/44181490713.pdfIn PDF document text
    • https://salogisamokowo.weebly.com/uploads/1/3/4/6/134649366/midode-jenubasuj-nopenim.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4476566/normal_6020a8cb166ae.pdfIn PDF document text
    • https://vizefibamoraxob.weebly.com/uploads/1/3/4/6/134613498/9764060.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4482230/normal_5fff66336e3b5.pdfIn PDF document text
    • https://cdn.sqhk.co/xasurila/jhOhhgf/alone_season_7_winner_roland.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4426271/normal_5fc6197819452.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://s3.amazonaws.com/tutapaxi/26495631494.pdfIn PDF document text
    • https://s3.amazonaws.com/divelatoxa/guide_to_etiquette_and_modern_manners.pdfIn PDF document text
    • https://s3.amazonaws.com/lanorolowu/kokusi.pdfIn PDF document text
    • https://s3.amazonaws.com/fewunadupop/50693792962.pdfIn PDF document text
    • https://s3.amazonaws.com/fajixe/loxubanedotozetifebefixat.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fc92.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC92 5876 bytes
SHA-256: 6deb5ef0c93f03a32236468bf0ce5d2af59022889c0346f9a3dbb65d0f024d84
font_01_sfnt_off0001106f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1106F 10584 bytes
SHA-256: e8aadfa41bc86238dd6c86099f110480fe57260ad597c71c8aa3d790e3807002
font_02_sfnt_off000134c7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x134C7 4324 bytes
SHA-256: a542ec26cea93e049a2e27cd59b1347dd9bbdea13775fd7b822b3c2b3136116f