Malicious PDF — malware analysis report

Static analysis result for SHA-256 813acda61ee446a7…

MALICIOUS

PDF

80.3 KB Created: 2021-03-14 01:13:29 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d9e2ce9e5f798e271bcbaa8d80312db5 SHA-1: d9b935f7fa96cabd9252c361bc7088a3a1130e62 SHA-256: 813acda61ee446a7d7c8404fd1b54fe121cca6b4444398049a876614c1a78602
186 Risk Score

Malware Insights

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

The PDF file contains a significant number of external links, identified as a link farm, with one prominent URL being `https://jumiwimov.ru/strik?utm_term=black+steel+pipe+fittings+melbourne`. This heuristic, combined with ClamAV detection and ML classification, strongly suggests a malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the PDF structure itself is used to facilitate the malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://jumiwimov.ru/strik?utm_term=black+steel+pipe+fittings+melbourne
    • http://bupro.asia/valovupobenudelhkzqi.pdf
    • https://bugasidajuw.weebly.com/uploads/1/3/1/8/131856032/7578372.pdf
    • https://rixutabenenik.weebly.com/uploads/1/3/4/4/134498467/mobowopil.pdf
    • https://cdn.sqhk.co/tawunipufop/IxjbOhM/guide_for_zoom_cloud_meeting_app_download.pdf
    • http://gufutaca6.xyz/did_mark_watney_die_in_the_martianwnnxd.pdf
    • http://tevfikyuce.xyz/xapuxakexedisijusevak2xydo.pdf
    • https://cdn.sqhk.co/kizusuvut/hhItgfr/30469075854.pdf
    • https://cdn.sqhk.co/xagaxubibiz/hhm0ggO/72201511626.pdf
    • https://poxovoxi.weebly.com/uploads/1/3/5/3/135398301/a7756edd0aeedbd.pdf
    • http://pestore.pro/74242107015dsp02.pdf
    • https://cdn.sqhk.co/veladaxuzeba/oshinja/blink_for_blackpink_pix_quiz.pdf
    • https://cdn.sqhk.co/kopilixa/2hihihj/51436599532.pdf
    • http://changely.club/16523313408ke3lc.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://s3.amazonaws.com/jojitagifuva/nibujafuramegomo.pdf
    • https://9849c7ec-8b19-4b81-9a64-db2537ea7c40.filesusr.com/ugd/97b1c0_0ccf914c309b476cbb6c0f44b6741ed1.pdf?index=true
    • https://770ad53b-b55e-4e58-b1eb-3709f41304f7.filesusr.com/ugd/98e298_79ca82bb761143ac84b5cf780bbcad44.pdf?index=true
    • https://3bdad275-8828-414d-9063-9532e035d791.filesusr.com/ugd/c67d0c_e84c87cf1e5a43ba967298813d67eadc.pdf?index=true
    • https://c208ddc4-37ec-4cef-823d-79aeaa8cd68a.filesusr.com/ugd/d34c4d_4a39d1730b7e4822aee687b1154049c5.pdf?index=true
    • https://s3.amazonaws.com/salosibejodod/whatsapp_arabic_stickers.pdf
    • https://s3.amazonaws.com/vizegemawokaxe/binomial_expansion_for_fractional_powers_proof.pdf
    • https://02274cc9-8b57-4441-be19-e46c089ec46b.filesusr.com/ugd/f11b8f_19c7c33144a7419b8690d913c75bf091.pdf?index=true
    • https://cad90261-f038-4e8a-b384-2e0e37e6cb8c.filesusr.com/ugd/4c4e45_7962658f60f8412986f3513fffe9a2d2.pdf?index=true
    • https://53ebb62d-ddaf-432f-8dc3-1f4746653467.filesusr.com/ugd/bbd3cf_3450bf568194434db41544be1624dd73.pdf?index=true
    • https://s3.amazonaws.com/jukezeluf/what_books_are_in_the_da_vinci_code_series.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_off0000ee7a.bin
a2072247c7954db2cb82ef36397fe02565080aef39d5e4718a2fd3ea70d87f84
pdf-font-stream PDF embedded font (sfnt) at offset 0xEE7A 5472 bytes
font_01_sfnt_off000100f5.bin
e909964f28a4d407f5f805f40e4f73f41213548532df297ee8c763fd3f313de1
pdf-font-stream PDF embedded font (sfnt) at offset 0x100F5 10808 bytes
font_02_sfnt_off00012598.bin
ff5f0ef16caf3e97cd1984b3a03ea88e11eab8cf63d2ee006085a4b9995833f3
pdf-font-stream PDF embedded font (sfnt) at offset 0x12598 4324 bytes