Malicious PDF — malware analysis report

Static analysis result for SHA-256 67a7b96fd0461221…

MALICIOUS

PDF

45.2 KB Created: 2020-08-23 13:40:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 71bfbd119e47484902acd5cfcfce387b SHA-1: 01aef7dc450de4da019660353af55a6af1fda20c SHA-256: 67a7b96fd04612214e381cd52a868c2d7201caeb51f314b569e215044e1450e5
154 Risk Score

Malware Insights

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

The PDF contains a link that redirects to known malicious infrastructure, disguised as interview questions. The ML classifier strongly indicates maliciousness, and the presence of numerous external PDF links suggests a link farm or SEO poisoning attempt. No scripts were extracted, but the primary attack vector is the malicious redirector URL.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://ttraff.ru/pify?keyword=teachers+assistant+interview+questions+and+answers
    • http://suleduwo.autosourceweekly.com/uploads/1/3/0/8/130873951/9272604.pdf
    • http://files.icellw.com/uploads/1/3/1/4/131406140/baradet.pdf
    • http://files.bristoldoughnut.co/uploads/1/3/1/1/131164002/2596418.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://cdn.shopify.com/s/files/1/0432/0614/8255/files/kidivukibovajomubibeluru.pdf
    • https://cdn.shopify.com/s/files/1/0431/5735/6695/files/sedentarismo_2020.pdf
    • https://cdn.shopify.com/s/files/1/0434/5007/3240/files/break_even_analysis_lecture_notes.pdf
    • https://cdn.shopify.com/s/files/1/0434/8398/8125/files/daz_loader_mydigitallife.pdf
    • https://cdn.shopify.com/s/files/1/0435/2599/6698/files/8th_grade_pre_algebra_worksheets.pdf
    • https://cdn.shopify.com/s/files/1/0431/8180/1629/files/wedding_invitation_website_templates_free.pdf
    • https://cdn.shopify.com/s/files/1/0436/4474/7929/files/62563945910.pdf
    • https://cdn.shopify.com/s/files/1/0440/9799/4904/files/amazing_grace_chris_tomlin_piano.pdf
    • https://cdn.shopify.com/s/files/1/0430/3867/1010/files/54018683983.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_off00006671.bin
a484f32eb43b154eaf31cafdac654d8698ca09c997b9c270296e41fd78f148aa
pdf-font-stream PDF embedded font (sfnt) at offset 0x6671 5104 bytes
font_01_sfnt_off000077cf.bin
8b0ef859508c3fdf437610dc59eaefdde05b952f27cdde12fccb7cb33012f7a1
pdf-font-stream PDF embedded font (sfnt) at offset 0x77CF 9988 bytes
font_02_sfnt_off000099f1.bin
1062cd8ddf90f4344fa193b395386d5669df1a952e5759311ca261a71931f361
pdf-font-stream PDF embedded font (sfnt) at offset 0x99F1 4324 bytes