Malicious PDF — malware analysis report

Static analysis result for SHA-256 5fe99540cb59929c…

MALICIOUS

PDF

81.4 KB Created: 2021-04-03 23:04:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 7a5740f2fb1b7f32a55832e1268732a0 SHA-1: ecef5e79ad19814b458203cf1ff1031889230751 SHA-256: 5fe99540cb59929c970ed96a14aee28163aa8bafd23f070ed72a6608f55af934
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many pointing to disposable hosting, indicating a link farm or SEO manipulation tactic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://golowaki.ru/strik?utm_term=top+big+data+analytics+companies+in+usa
    • https://cdn-cms.f-static.net/uploads/4455381/normal_6049cf0d1c3ac.pdf
    • https://cdn.sqhk.co/zedawuzijis/idahaS1/average_age_of_cavemen.pdf
    • https://puzejiwitamino.weebly.com/uploads/1/3/1/4/131453698/8909344.pdf
    • https://cdn.sqhk.co/kalijada/hfLhjpz/order_contacts_online_with_unitedhealthcare_insurance.pdf
    • https://cdn-cms.f-static.net/uploads/4403429/normal_6049f035a165d.pdf
    • https://xelemurefitarag.weebly.com/uploads/1/3/4/6/134601467/wejebel-wevidoravuva.pdf
    • https://cdn.sqhk.co/defisepeniba/Kjbhejj/free_printable_small_business_plan_template.pdf
    • https://cdn-cms.f-static.net/uploads/4370561/normal_605b03a9ca1ad.pdf
    • http://sobuvide.mygamesonline.org/58037549804.pdf
    • https://cdn.sqhk.co/legezuseg/jbOEjet/kefiwokitavive.pdf
    • https://cdn.sqhk.co/vovewotutal/r9jcPgc/fuzase.pdf
    • https://baxelawinojiw.weebly.com/uploads/1/3/4/3/134333718/pawoxogofugoze.pdf
    • https://niritopep.weebly.com/uploads/1/3/4/6/134634222/6c87b0a.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://37523d11-79cf-4eb3-ada4-f05de57c71ee.filesusr.com/ugd/275374_3986cd85691d4165bbf1e37e9cceebe8.pdf?index=true
    • https://74fc1a11-d445-4ffb-bc6b-7a79e5a65a18.filesusr.com/ugd/097bd5_22af6a953a244a9eab691bae6b879de8.pdf?index=true
    • https://43fe4710-460a-4ad3-90dc-2dd795c51528.filesusr.com/ugd/a32c20_fd1c0a42931248019e51b9561ca72dd3.pdf?index=true
    • http://muvekalufisu.atwebpages.com/etiology_of_mental_illness.pdf
    • https://a12a05ab-6462-4855-b086-b0a2a961d6d8.filesusr.com/ugd/2c76f4_b311297106154e18ba385b86ddaaf776.pdf?index=true
    • https://245ae9ba-e923-43ed-bc11-30ed5d1acd78.filesusr.com/ugd/051519_7095dec07b1a4be9bb988b81612f0d52.pdf?index=true
    • https://38aad9b5-7a72-45b8-ac81-9fe73ce82000.filesusr.com/ugd/08338c_86b205e188804944867cc1feb8bece28.pdf?index=true
    • https://fea50346-ab34-4b67-843e-90a6383c4983.filesusr.com/ugd/bf678e_0f6fb19c7cfe4870b73eb9eea4008218.pdf?index=true
    • https://769966b8-4adc-437e-bba8-f198cf6e171b.filesusr.com/ugd/41a0b6_88154c1fa46441e68a727694c53c2758.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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fd9a.bin
a17d5c4a94e4f398f60a056a5e6e10d5fd11d46ab2f289b290ebbc9bc0d0e8e6
pdf-font-stream PDF embedded font (sfnt) at offset 0xFD9A 5488 bytes
font_01_sfnt_off0001103e.bin
a771f4ad08506a46b500f89cd32054dca08f171f3ecc0236f2da7f5ce2fea6f2
pdf-font-stream PDF embedded font (sfnt) at offset 0x1103E 11248 bytes