Malicious PDF — malware analysis report

Static analysis result for SHA-256 154b6c5b07c218d9…

MALICIOUS

PDF

81.6 KB Created: 2021-06-02 21:50:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 8c39aee70f9bccffee45795786e5b83f SHA-1: d1e3af9091c1814afbfc79b21d54f94462e92422 SHA-256: 154b6c5b07c218d9c2ded64627809cde242be889c049ae6c81b0dcc74c0ef087
186 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous external links to other PDF files hosted on various domains, some of which appear to be disposable. The presence of these links, particularly those with UTM parameters, suggests an attempt to manipulate search engine results or distribute further malicious content. No scripts were extracted, and the document body was heavily obfuscated, preventing a deeper analysis of its specific payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://jottigo.ru/123?utm_term=driving+school+classics+apk+mod+revdl
    • https://bisaderivulele.weebly.com/uploads/1/3/4/7/134744485/bezixuxa.pdf
    • https://buzapakamewogu.weebly.com/uploads/1/3/4/3/134366326/gupateme-gugamogozuvalaw-wujobomatopuput.pdf
    • https://static.s123-cdn-static.com/uploads/4444357/normal_5fe201e0604a9.pdf
    • https://xujoxufopugapes.weebly.com/uploads/1/3/1/3/131380539/903587.pdf
    • https://cdn-cms.f-static.net/uploads/4368468/normal_606e5f736a565.pdf
    • https://mifafipuwekirej.weebly.com/uploads/1/3/5/3/135327035/vofuzebokusotu_nowamamafara_pejes.pdf
    • https://dijozigi.weebly.com/uploads/1/3/4/7/134748041/koboxinunidadago.pdf
    • https://bezesigut.weebly.com/uploads/1/3/2/6/132681157/gusubesugugog.pdf
    • https://lumewogomor.weebly.com/uploads/1/3/4/3/134319436/2094318.pdf
    • https://cdn-cms.f-static.net/uploads/4386607/normal_5feaf63785787.pdf
    • https://sesupukaxupasi.weebly.com/uploads/1/3/1/0/131070911/xorinuwabosugabisez.pdf
    • https://joxeluduxena.weebly.com/uploads/1/3/4/7/134772203/tisomafixir.pdf
    • https://static.s123-cdn-static.com/uploads/4413111/normal_5ff0b0b7b927c.pdf
    • https://zowadite.weebly.com/uploads/1/3/1/3/131380399/bibirejuv.pdf
    • https://loxazofobel.weebly.com/uploads/1/3/4/2/134265844/budodomavovejo-tunog.pdf
    • https://rogenogenitel.weebly.com/uploads/1/3/4/3/134316557/fipatoloromanuxoxa.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://podixarutib.pbworks.com/f/exercices_sur_les_fractions_dcimales_cm1__imprimer.pdf
    • https://uploads.strikinglycdn.com/files/fae95a96-8f7f-4b64-ac9d-49f22ef2a69b/fidagupegigidigoz.pdf
    • http://zewalar.pbworks.com/w/file/fetch/144454548/1885926395.pdf
    • https://uploads.strikinglycdn.com/files/cedff66c-f44d-49f9-a5db-239605cbcc7d/what_is_the_simplified_form_of_120_100.pdf
    • http://foziwedugumu.pbworks.com/f/abo_and_rh_blood_typing_lab_answers.pdf
    • http://tozuxexap.pbworks.com/w/file/fetch/144517476/junajubonovewuwitebo.pdf
    • https://uploads.strikinglycdn.com/files/13c30fa8-c25d-4beb-adaf-c7060e90fde7/98950074502.pdf
    • http://neruwuk.pbworks.com/w/file/fetch/144420417/how_to_enter_bios_acer_predator_helios_300.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f618.bin
5b7937cc86a4c9803a6fffcea36377c49dda53178d4c52474c5ef261971d2a75
pdf-font-stream PDF embedded font (sfnt) at offset 0xF618 5612 bytes
font_01_sfnt_off00010916.bin
c27bdbf4c98cfa83ff07caf63da9cadf09b5442006466f2c537707f66f344278
pdf-font-stream PDF embedded font (sfnt) at offset 0x10916 21804 bytes