Malicious PDF — malware analysis report

Static analysis result for SHA-256 fe7bd9fdb6c58323…

MALICIOUS

PDF

76.7 KB Created: 2021-03-05 15:36:21 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-13
MD5: 73b7e97903262fe9a17d408716a3043b SHA-1: 914037a4d5cf87af858410164bd97bf9b591a140 SHA-256: fe7bd9fdb6c58323ff10b9927161533df9f6a94c70d75359a2fd92fbe0cb176f
126 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many hosted on disposable domains, indicating a link farm or SEO spamming operation. One prominent URL, https://jacksth.ru/strik?utm_term=how+to+pair+onn+earbuds, suggests a lure related to pairing earbuds. The ML classifier strongly flagged this PDF as malicious, and the presence of numerous external links points towards an attempt to redirect users to potentially harmful content.

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.
  • 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://jacksth.ru/strik?utm_term=how+to+pair+onn+earbuds PDF link annotation
    • http://zuzorovix.scienceontheweb.net/apush_amsco_book_2015.pdfIn PDF document text
    • http://woxuruko.medianewsonline.com/australian_native_wild_dogs.pdfIn PDF document text
    • https://xisezuvu.weebly.com/uploads/1/3/4/0/134096300/kizafatate-bawaxobin-jabexugu.pdfIn PDF document text
    • http://vedoluzomo.iblogger.org/non-destructive_testing_specialists_salary.pdfIn PDF document text
    • https://zoxujaratufopa.weebly.com/uploads/1/3/5/3/135399722/zaguminop.pdfIn PDF document text
    • https://gozexorajive.weebly.com/uploads/1/3/4/6/134610068/pafevas.pdfIn PDF document text
    • https://tababara.weebly.com/uploads/1/3/0/7/130739165/vijufulimapuram_bewurope_nuvevu_genubo.pdfIn PDF document text
    • https://gitujibexilen.weebly.com/uploads/1/3/1/4/131406430/vajunexepupivikober.pdfIn PDF document text
    • https://jugotogosef.weebly.com/uploads/1/3/0/8/130814460/cc1de.pdfIn PDF document text
    • http://mutujejeturuduf.medianewsonline.com/linear_equations_examples.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://rujidafedisezu.atwebpages.com/47190865747.pdfIn PDF document text
    • http://mogazijanadoro.rf.gd/bizosonavisopuli.pdfIn PDF document text
    • http://tasefabomodewiv.epizy.com/android_phone_reverse_image_search.pdfIn PDF document text
    • http://tawatibajat.rf.gd/jax_beach_surf_report_magicseaweed.pdfIn PDF document text
    • http://sovotovagito.epizy.com/kigulolonenigiw.pdfIn PDF document text
    • http://gakilasefit.myartsonline.com/what_happens_if_you_fail_your_road_test_in_nj.pdfIn PDF document text
    • http://gaxilitexu.onlinewebshop.net/vitamix_blender_sale_kohls.pdfIn PDF document text
    • http://gurabagoderes.atwebpages.com/pentair_triton_ii_tr60_laterals.pdfIn 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_off0000f1d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1D9 5112 bytes
SHA-256: bcfcca7809e8d81d0f7f954063265e4b13607180b815ff4fe962062952421cfb
font_01_sfnt_off0001034f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1034F 10192 bytes
SHA-256: 7326de41c66cdd521fccebd776c8156e944176b8111bb7a94fd09705ce2807c9