Malicious PDF — malware analysis report

Static analysis result for SHA-256 77db38fb95a48c7b…

MALICIOUS

PDF

72.4 KB Created: 2021-03-31 06:25:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ff6513455b3170ac5f849437e3db9916 SHA-1: 9621574fcb10a964522bd393685aee416b1f8058 SHA-256: 77db38fb95a48c7b8b7a7b0cd2f11158a2ad4026f5626165cc16ffdf84308be8
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 of which are to benign-looking documents but are likely part of a link farm or SEO manipulation scheme. The ClamAV detection and ML classifier strongly indicate malicious intent, specifically identified as a phishing trojan. While no scripts were explicitly extracted, the PDF structure and numerous external URIs suggest an attempt to redirect users to malicious sites, potentially for phishing or malware distribution.

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://dafemum.ru/award?keyword=life+cycle+of+an+insect+pdf
    • https://deserekinubolid.weebly.com/uploads/1/3/4/3/134319780/soripon.pdf
    • https://cdn.sqhk.co/zugivakizo/gerMnic/plants_vs_zombies_free_playing.pdf
    • http://apparentlyopt.com/runivatonotexudtgz5b.pdf
    • https://cdn.sqhk.co/noligigibar/xhhhbDN/mifamusalewasikabunu.pdf
    • https://palegovod.weebly.com/uploads/1/3/1/0/131070329/3339941.pdf
    • https://cdn.sqhk.co/fewesiwe/HgehgRt/metro_textiles_london.pdf
    • http://betomererag.iblogger.org/does_god_have_power.pdf
    • https://cdn.sqhk.co/numexerab/BXGjggj/jujafafudigukomix.pdf
    • https://jozufibajas.weebly.com/uploads/1/3/0/9/130969385/tipunijesiwaz-sivifupox-basadi.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://s3.amazonaws.com/watajive/how_to_draw_christmas_tree_in_easy_method.pdf
    • https://s3.amazonaws.com/gonima/91536384976.pdf
    • https://s3.amazonaws.com/dutuzanob/36642293550.pdf
    • https://s3.amazonaws.com/nojemi/japiwet.pdf
    • https://s3.amazonaws.com/fazujo/how_to_turn_on_tv_using_xfinity_remote_app.pdf
    • http://kelamivajaw.rf.gd/internet_speed_indicator_apkpure.pdf
    • https://s3.amazonaws.com/tibitexil/excel_sheet_synonym.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_off0000ddde.bin
3c6183864dcc77e1302b7532805f1d7018119d009c025f51b5166cf6e0752c3c
pdf-font-stream PDF embedded font (sfnt) at offset 0xDDDE 5096 bytes
font_01_sfnt_off0000ef60.bin
f01fe54e4667a7fbffe85dc73c091c672f48ce4abcf849b6134156d2b3432186
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF60 10424 bytes