Malicious PDF — malware analysis report

Static analysis result for SHA-256 435da11ee7142d7e…

MALICIOUS

PDF

68.5 KB Created: 2021-03-30 21:33:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 4628b01af5a0b50da3b7f55c86492a5d SHA-1: e5fac01bbb2e3be5b60a667ca635807abad310b2 SHA-256: 435da11ee7142d7e9f75b910eb9c2b2f8eadaf24e53b586485935fc2c0df33a3
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, identified as a link farm. The primary URL, https://jottigo.ru/123, suggests a lure for engagement or invitation, which is likely a pretext to direct users to malicious content hosted on the numerous other domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution via the linked PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • 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 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://jottigo.ru/123?utm_term=engagement+invitation+background+template PDF link annotation
    • http://tokio-2020.fun/wosomop93f81.pdfIn PDF document text
    • https://witomoniwitu.weebly.com/uploads/1/3/5/3/135317652/vatofivivajuwemilate.pdfIn PDF document text
    • http://energytik.net/4696131404916zbw.pdfIn PDF document text
    • http://wildboost.club/91423263956vp1he.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4384323/normal_605b760a87aa1.pdfIn PDF document text
    • http://sijazoge.iblogger.org/89725176775.pdfIn PDF document text
    • https://pimapavidi.weebly.com/uploads/1/3/2/7/132740410/wovab.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4447663/normal_5ffb919c15c44.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4445116/normal_5ff864e96e370.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4388040/normal_6015fe1aa7837.pdfIn PDF document text
    • http://lessonsonline.site/religious_trust_deed_format_in_word3qdfq.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4445116/normal_6002bc9197c0d.pdfIn PDF document text
    • http://fkpravo.ru/56492962654sqook.pdfIn PDF document text
    • https://tesetugunujogub.weebly.com/uploads/1/3/4/0/134040467/xewaxefuzup_jezetovasajej_tabigalexuto.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://dinijeti.rf.gd/42092807364.pdfIn PDF document text
    • https://42172c5f-463d-425f-bc49-3536d5e9b788.filesusr.com/ugd/3e9aab_4010c6007e8c443c97584691936ba724.pdf?index=trueIn PDF document text
    • http://bikutuvuxaxixo.epizy.com/unit_5_synonyms_and_antonyms_answers.pdfIn PDF document text
    • https://8fa10226-37c2-454d-bd65-ced70ecbf0c4.filesusr.com/ugd/c34aa9_fa13ec521fbc45bfada90fd4cf34c223.pdf?index=trueIn PDF document text
    • https://73af689e-4c80-4f62-99d3-7a886641ad81.filesusr.com/ugd/3b5dd9_832d00266e2645f49d8f4df65426b2aa.pdf?index=trueIn PDF document text
    • http://widamifikifewex.epizy.com/wapezujirakevenejugogolus.pdfIn PDF document text
    • https://cae2aa39-5014-47ec-b549-0fed73f36d02.filesusr.com/ugd/c8683e_c134825d8f7f419886ad0d132a9a277c.pdf?index=trueIn PDF document text
    • http://sexuroduveso.rf.gd/rzr_1000_transmission_service.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_off0000cfca.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFCA 5436 bytes
SHA-256: df51ab557f76f046165d8e646985cf06035e9c75a17ed35ae3f5fc32f7db8695
font_01_sfnt_off0000e240.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE240 10068 bytes
SHA-256: 4f3972a90f68314b96e2514c9f4cea784cd321bf41038d918acbb827aa3b3094