Malicious PDF — malware analysis report

Static analysis result for SHA-256 a61bae58a33649ad…

MALICIOUS

PDF

79.4 KB Created: 2021-03-19 06:37:03 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1fa69d4fc403eefe611faf789a202960 SHA-1: 2a0132c1d0ece4eef32acfcc7f0bf8165457a3d5 SHA-256: a61bae58a33649ad6d183927b8c44d6f2c097827c75739c72d9dc9c834802f0a
196 Risk Score

Malware Insights

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

The sample is a PDF file that employs a social engineering tactic, specifically a browser extension/update installation lure, to trick users into compromising their systems. It contains numerous external links, some of which are part of a link farm, and is flagged by ClamAV as a phishing trojan. The presence of embedded URLs and the ML classifier's high confidence score indicate malicious intent, likely to download and execute a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Browser extension / update installation lure high SE_BROWSER_INSTALL_LURE
    Document tells the user to install a browser extension, plugin, viewer, or browser update to view content — a common social-engineering path for credential theft and malware installation
  • 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/strik?utm_term=h2o+mop+x5+elite+canadian+tire
    • https://cdn-cms.f-static.net/uploads/4369935/normal_5fd16408e062d.pdf
    • https://cdn-cms.f-static.net/uploads/4445118/normal_5fdc6e78654dc.pdf
    • https://devudupaf.weebly.com/uploads/1/3/4/8/134880603/bf1df51b631.pdf
    • http://pochta-24.cc/data_warehouse_tools2kyp2.pdf
    • https://cdn-cms.f-static.net/uploads/4458389/normal_5fd176967914d.pdf
    • http://istlan.space/c_b_i_shankar_songsqbqwf.pdf
    • https://tevukebejesa.weebly.com/uploads/1/3/2/6/132695492/fa104b2b3fb7.pdf
    • http://reform-st.ru/outlining_your_novel_templaterokpq.pdf
    • https://static.s123-cdn-static.com/uploads/4484364/normal_5ff37dce9f60a.pdf
    • https://legaxebojidonet.weebly.com/uploads/1/3/0/7/130775342/fibabikuzekumal.pdf
    • https://dorulitonen.weebly.com/uploads/1/3/1/3/131380258/9097793.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/7a81a147-9f19-4405-a618-629345100375/tumi_carry_on_luggage_with_charger.pdf
    • https://d12e84a0-9808-45da-82c6-613dfe540d1b.filesusr.com/ugd/dc8a8e_ee19c952d3fe4d028cafc8e56209ae19.pdf?index=true
    • https://5090c2af-253d-40c3-bfb7-942fc6db26b0.filesusr.com/ugd/0511f5_034569dc5e424a43b1015b4fdd48f882.pdf?index=true
    • https://uploads.strikinglycdn.com/files/769ccab2-9e8c-49e3-b9eb-a287bd77fdde/ea_sports_ufc_3_pc_download_key.pdf
    • https://6db1e9a2-4282-4636-8d41-de07325ad911.filesusr.com/ugd/d97b38_0ebfe11ebda448e5860b758caeb58236.pdf?index=true
    • 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
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000db87.bin
1612314b1124bb9a7f8452ab7174169eeb5349b02d7f6f26f616a4770357b23f
pdf-font-stream PDF embedded font (sfnt) at offset 0xDB87 5328 bytes
font_01_sfnt_off0000ed9a.bin
51349a940f2a2072b9e35ee3207dca3e3b3a9d9cfbe91a3470ead9cd2d2b0835
pdf-font-stream PDF embedded font (sfnt) at offset 0xED9A 12776 bytes
font_02_sfnt_off0001183c.bin
3913634ec95daa34ea55d31fc213633e92460b0d84646d706317e58237d62a18
pdf-font-stream PDF embedded font (sfnt) at offset 0x1183C 16580 bytes