Malicious PDF — malware analysis report

Static analysis result for SHA-256 6e81d5a1325c235d…

MALICIOUS

PDF

78.8 KB Created: 2021-04-05 14:28:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 1f571b60da2bb37e1b824366bf5d311b SHA-1: e9edb89237a71b8d130e2dde3c123f5c6663de8b SHA-256: 6e81d5a1325c235d83ff00b2f24ca5d211e0fb17ca3d523fc962d89909c5e602
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a large number of external links, many hosted on disposable domains, characteristic of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or SEO spam. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose beyond the presence of links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://jumiwimov.ru/123?utm_term=exothermic+and+endothermic+reactions+gcse+worksheet
    • http://simopuvoramawu.mywebcommunity.org/spanner_types.pdf
    • https://zitejapaj.weebly.com/uploads/1/3/1/8/131872087/cada5b3255882.pdf
    • https://sekamaxe.weebly.com/uploads/1/3/4/5/134590712/rulavopafo-gewibuxewavu-benalegeni-lijozov.pdf
    • https://suvukesirer.weebly.com/uploads/1/3/4/3/134316802/cab539.pdf
    • https://wivaralizufijol.weebly.com/uploads/1/3/1/4/131483386/1723755.pdf
    • https://nonafinawajag.weebly.com/uploads/1/3/4/3/134331790/vutatenud.pdf
    • https://fomezesas.weebly.com/uploads/1/3/4/3/134343882/5716729.pdf
    • https://kapizufon.weebly.com/uploads/1/3/4/4/134486886/8600980.pdf
    • https://kuruxeronujupo.weebly.com/uploads/1/3/4/4/134477992/103fe22.pdf
    • http://xiwakaravivomik.scienceontheweb.net/pekasujoxe.pdf
    • http://lulilafemavivog.mygamesonline.org/clinical_pharmacology_made_ridiculously_simple_5th_edition.pdf
    • http://jufanurozud.getenjoyment.net/lejaxiraposomaletif.pdf
    • https://dizuxegukus.weebly.com/uploads/1/3/4/6/134624336/b10e4cde2130.pdf
    • https://nuvafuriwevejuf.weebly.com/uploads/1/3/2/8/132814848/450747e1.pdf
    • https://loleritukala.weebly.com/uploads/1/3/0/9/130969936/mamefumiw.pdf
    • https://revotilam.weebly.com/uploads/1/3/4/7/134732497/e51a6.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://d5fd0048-bb8d-45a1-ba21-28d1cb0b7162.filesusr.com/ugd/5e8de6_3fc2154f5ae14ce78470eccce818d95e.pdf?index=true
    • https://uploads.strikinglycdn.com/files/756847d4-2a21-41f5-be1b-d39e4424bd80/gulorefediwubilam.pdf
    • http://tiwosutodegadax.onlinewebshop.net/alimentos_que_favorecen_absorcion_de_hierro.pdf
    • https://uploads.strikinglycdn.com/files/4593e4ab-1995-4699-ae97-6ea1eb604533/kulidudaruso.pdf
    • https://be9c8297-50e9-4ec8-be22-7cc4068ef96a.filesusr.com/ugd/fc3b0b_529ee64e242745d196985621f5b11ceb.pdf?index=true
    • https://c1cb471f-fc5c-4ef2-b3e1-4d0d0d09d135.filesusr.com/ugd/cc5b41_c1e4513e38394354a39000818e96ba9a.pdf?index=true
    • https://4b4b92a8-4ac5-4030-97d5-af0917f8c077.filesusr.com/ugd/0251f0_4cf88577ed9541d1bed7c7b9f0f00de5.pdf?index=true
    • 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
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e034.bin
ffa0a25be544d3e435bf5bd00a0f805d2d9914e5e2bd307f70491fab1ec651fe
pdf-font-stream PDF embedded font (sfnt) at offset 0xE034 5500 bytes
font_01_sfnt_off0000f2d5.bin
b4ab63acecee0356a389445351a725480d1812728068c38ecb386a43f3458394
pdf-font-stream PDF embedded font (sfnt) at offset 0xF2D5 10772 bytes
font_02_sfnt_off000117b8.bin
b2ddecaff7e2361bf51021b35f9c014659943b600c4f466cb4656cea9e83b80e
pdf-font-stream PDF embedded font (sfnt) at offset 0x117B8 16088 bytes