Malicious PDF — malware analysis report

Static analysis result for SHA-256 aa8c17390786e512…

MALICIOUS

PDF

87.3 KB Created: 2021-06-06 02:30:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-18
MD5: 2a9699b160eecf0c7f8bedf41b1a6a63 SHA-1: b7e63827bdb282048741b623dbde36afc25f9e19 SHA-256: aa8c17390786e512b3d46e9b5be3d117f4291af883b0647bc5a3fe348d0f9310
186 Risk Score

Malware Insights

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

The PDF document contains a large number of external links, many hosted on disposable domains, indicating a link farm designed to manipulate search engine results or direct users to malicious sites. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. No scripts were extracted, but the presence of numerous external URLs is the primary indicator of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://nipisod.ru/123?utm_term=hse+confined+space+permit+to+work+template PDF link annotation
    • https://kagozekexep.weebly.com/uploads/1/3/5/9/135956698/48c933f.pdfIn PDF document text
    • https://tusixifowidafoj.weebly.com/uploads/1/3/1/4/131437116/1a787c8005fa4.pdfIn PDF document text
    • https://static.s123-cdn-static-d.com/uploads/4371025/normal_60b1d560811fc.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4443329/normal_5ff80e36eb959.pdfIn PDF document text
    • https://fofosaja.weebly.com/uploads/1/3/4/2/134234592/6c38c431a5f331f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4479942/normal_5fd64c4ced948.pdfIn PDF document text
    • https://tetavezodumop.weebly.com/uploads/1/3/4/6/134645623/2783079.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4385847/normal_60622b465ad91.pdfIn PDF document text
    • https://powipawi.weebly.com/uploads/1/3/4/3/134313445/213a7a022820e.pdfIn PDF document text
    • https://ledobosu.weebly.com/uploads/1/3/1/3/131383424/wezomaparote.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/c6a607e1-2e7d-410b-bc67-c765125dffb9/how_do_i_convert_a_to_word_doc_on_mac.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a0b265e1-2122-4e71-8ca5-b9022ea61bf1/i_passed_my_walmart_assessment_test.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/738d8439-99e9-4b4e-a2fd-138be23bec49/is_dragon_sign_lucky_in_2020.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6ce1fff4-6bcf-40b4-8ba7-e2f8d347da4f/93634633339.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d9780541-d5e7-4792-b602-e430c56e0830/914076056.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/6f644c2c-bbed-4890-b05e-52f7d539dde2/how_to_print_on_epson_wf_2630.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4c9c8662-2f55-4aec-96fb-1e64e5bbf6f5/california_common_core_science_standards_3rd_grade.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_off0001188c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1188C 5416 bytes
SHA-256: 6473646c45cb3b069821b011e0783329fb163ca2e13de6d5c0c4149ec13f1650
font_01_sfnt_off00012af9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AF9 10732 bytes
SHA-256: 9ffa0749da17ebfea1e75115a68627dcb3aa8decfc751f0fc321491ea1b76857