Malicious PDF — malware analysis report

Static analysis result for SHA-256 4cf4f4bac7b45830…

MALICIOUS

PDF

86.9 KB Created: 2021-03-12 00:26:17 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: dd68a4964bdc965770f3dd110034e608 SHA-1: 8edf66382b5972fa72a864ac536878eab5c1f247 SHA-256: 4cf4f4bac7b45830a29899afd661e4a009f234fa00a226b640eb7132fa22d6b8
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 pointing to S3 buckets and other domains, suggesting a link farm or SEO spam operation. The ClamAV detection and ML classifier indicate malicious intent, likely phishing or malware distribution. No scripts were extracted, but the PDF structure itself is used to host numerous external URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://resalured.ru/award?keyword=materiales+ceramicos+tradicionales+pdf
    • https://laxedojopepab.weebly.com/uploads/1/3/4/8/134896069/rizetawog.pdf
    • http://sreview.online/dolphin_emulator_32_bitcsxuz.pdf
    • https://pojewesam.weebly.com/uploads/1/3/1/4/131410485/vomowetafanitu.pdf
    • http://design-kvartira.info/difuvozobolokudhoj8k.pdf
    • http://spoonnumberone.xyz/tizanurofimae5ps.pdf
    • https://pigamudabuv.weebly.com/uploads/1/3/4/2/134235231/fomonibumizep.pdf
    • http://becloud.website/43584962014m09by.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/wowonesoribu/anime_slayer_android_2._3._6.pdf
    • http://pimebojozewo.rf.gd/84743230050.pdf
    • https://s3.amazonaws.com/wewiro/kupuf.pdf
    • https://s3.amazonaws.com/muxegeza/alaska_drivers_permit_test.pdf
    • https://s3.amazonaws.com/miledu/geometric_algebra_books.pdf
    • https://s3.amazonaws.com/jedobufudajewu/blue_eyes_video_song_720p_free.pdf
    • http://soxosodazafu.epizy.com/kajivisitip.pdf
    • https://s3.amazonaws.com/poguvelefa/sample_assessment_forms_for_preschoolers.pdf
    • http://moxutomib.rf.gd/cctv_cameras_installation.pdf
    • http://bowibimedex.rf.gd/uspstf_cervical_screening_guidelines.pdf
    • http://vorakufi.epizy.com/troy_bilt_tb230_parts_diagram.pdf
    • https://s3.amazonaws.com/bulikowexunepov/what_holidays_do_dollar_general_employees_get_paid_for.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_off000114b0.bin
bb34effc4f77f51e6f6618d61aded6788b9f33f0bcebe7cf357970cd6ac20a2d
pdf-font-stream PDF embedded font (sfnt) at offset 0x114B0 5304 bytes
font_01_sfnt_off000126b2.bin
95d2ceaefe625d18d4532f599fa46ba239992028505f32a5c5b6ecbfd07e4aef
pdf-font-stream PDF embedded font (sfnt) at offset 0x126B2 11844 bytes