Malicious PDF — malware analysis report

Static analysis result for SHA-256 caa54090875a0374…

MALICIOUS

PDF

77.5 KB Created: 2021-01-28 02:50:18 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-15
MD5: a328bb4f43265be18caf0f87bf9f71a9 SHA-1: 45a434e5d75a9308ec33a6fb651336c3b51e8c7d SHA-256: caa54090875a0374517e90d61933a33c5caea62e1e3c713dffb02dd6cfe1f134
254 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

This PDF file contains numerous links designed to redirect users to external websites, many of which host further PDF documents. One prominent redirector URL is https://yafferge.ru/123?utm_term=weighted+pressure+plate+uses, which is flagged as malicious. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the extensive link farm suggests a coordinated effort to distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://yafferge.ru/123?utm_term=weighted+pressure+plate+uses In PDF document text
    • https://static.s123-cdn-static.com/uploads/4493200/normal_5ff5231dc4d9e.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4367640/normal_5fd12bb95fd61.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4404296/normal_5feb4e710e194.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4426090/normal_5fc86c6aee247.pdfIn PDF document text
    • https://cdn.sqhk.co/jemitaso/jccsjjv/impossible_bike_stunts_3d_bike_racing_stunt_games.pdfIn PDF document text
    • https://cdn.sqhk.co/wugolekufo/rJjeBha/gym_flip_game_online.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4467285/normal_5fc866be8cf41.pdfIn PDF document text
    • https://cdn.sqhk.co/mavixuwaloz/gZgi25A/harry_potter_hogwarts_mystery_quidditch_head_or_heart.pdfIn PDF document text
    • http://copyrightnotices-form.com/very_best_of_the_eagles_cdwlx94.pdfIn PDF document text
    • https://jobalexaxikut.weebly.com/uploads/1/3/4/8/134892204/wezanolim.pdfIn PDF document text
    • https://gekitudofu.weebly.com/uploads/1/3/4/4/134403565/3031980.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4445115/normal_5ff04967dab13.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4368767/normal_5fe90201a403c.pdfIn PDF document text
    • http://subfamjtii.site/gatizesik43y8m.pdfIn PDF document text
    • https://cdn.sqhk.co/xulawajikigi/dijchi2/litexopesexixi.pdfIn PDF document text
    • https://cdn.sqhk.co/wezupobuwab/ggjabjj/word_blocks_app.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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_off0000ed7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xED7A 5236 bytes
SHA-256: b8678e3621b163f56aae3ecc8bdded6b9004fb46de2b145589e21e130e827f3b
font_01_sfnt_off0000ff4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF4F 12176 bytes
SHA-256: d182af593915d435a30f73f0ce62980ad506a493767a7c18324926086fe945e9