Malicious PDF — malware analysis report

Static analysis result for SHA-256 53dfd4519d244bc6…

MALICIOUS

PDF

98.7 KB Created: 2021-04-21 14:04:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 50ca35c56fa2331e72e768e00ba09a94 SHA-1: 7fcb3f2c26da241eef9f7a4532da983c52878b40 SHA-256: 53dfd4519d244bc6373baa5a60fc804169ec880edb42f108c32e48d2e79b8b48
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, indicating a link farm or SEO spamming operation. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards techniques used to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://nipisod.ru/strik?utm_term=el+principito+audio+libro+gratis
    • http://francobusiness.com/kohler_cv15s_carburetor_parts1g358.pdf
    • http://sportita.fun/dedizrfzht.pdf
    • http://nafarami.medianewsonline.com/msi_z97-g45_motherboard.pdf
    • https://nekemobo.weebly.com/uploads/1/3/5/3/135323096/1174824.pdf
    • https://welokanuxutumo.weebly.com/uploads/1/3/4/0/134017703/8979485.pdf
    • https://kanoritixuvu.weebly.com/uploads/1/3/4/8/134874131/2545630.pdf
    • http://bestita.space/4341662078smlgq.pdf
    • http://pokypka.xyz/why_wont_my_kenmore_refrigerator_make_ice87d6s.pdf
    • https://lawilutimi.weebly.com/uploads/1/3/4/8/134879912/9663331.pdf
    • http://daating19.site/kubota_bx_2380_specifications53ul0.pdf
    • http://ferategaj.scienceontheweb.net/35259969668.pdf
    • https://vuzevarezevarot.weebly.com/uploads/1/3/0/7/130740461/dinaf.pdf
    • http://xsale.trade/sim_brothel_2_downloado82wh.pdf
    • https://rowafitiw.weebly.com/uploads/1/3/4/6/134608100/wibegorod_dopedumologoxi_karewas.pdf
    • https://zodoxofavuzawa.weebly.com/uploads/1/3/1/4/131437464/gipetugilowafaviwu.pdf
    • https://vimavaduziwali.weebly.com/uploads/1/3/1/8/131856569/e398a17421.pdf
    • https://zizudenavoxe.weebly.com/uploads/1/3/4/0/134017195/tedadezedo.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://4abf464d-34d5-4c80-8de5-e64f30e04530.filesusr.com/ugd/8b3eb5_c931e2a03cd0440b98fae275c6cc7639.pdf?index=true
    • http://lejiletuvasipib.onlinewebshop.net/48743543034.pdf
    • https://f89b8795-a90f-4359-81e0-6309601a98d9.filesusr.com/ugd/8e7730_7c11ee6296ab455c96bee63906811aaa.pdf?index=true
    • https://d190c387-1498-4382-a59e-98d1a0a9794c.filesusr.com/ugd/a91264_df0a6b7e26bb43a9a33f7d8eb5fdbf3d.pdf?index=true
    • https://7f1888b6-cdab-4603-9914-1cf81a8b29aa.filesusr.com/ugd/6846fe_861eaa6c24a443c0a820b3d6bfa83000.pdf?index=true
    • https://2a4065d7-883d-43e8-a524-7ce9aa4b4e88.filesusr.com/ugd/ccb1c6_18a960a514cb41f7b48412bff5940dc0.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/
    • https://savannah.gnu.org/projects/freefont/
    • http://www.gnu.org/licenses/
    • http://www.gnu.org/copyleft/gpl.html
    • http://scripts.sil.org/OFL
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 5

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f774.bin
63b56845cf9a0b63bd1e0c615a76e231494e07ce049a896d11879254b756f20f
pdf-font-stream PDF embedded font (sfnt) at offset 0xF774 6676 bytes
font_01_sfnt_off0001084b.bin
08e51846ad41cf2ab77366dc822b5db1fbf72ac49513f5aa7ea88697475e481a
pdf-font-stream PDF embedded font (sfnt) at offset 0x1084B 5336 bytes
font_02_sfnt_off00011a72.bin
78d07d0794842fdf486743c2f3da6c32ffe786e42a41eb044a882d88a2eae929
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A72 11820 bytes
font_03_sfnt_off00013e9b.bin
fb22f8ad3b633ed88bf97da4f2feea2862493437235ca36c753398268a3491fe
pdf-font-stream PDF embedded font (sfnt) at offset 0x13E9B 12412 bytes
font_04_sfnt_off000165d3.bin
2f40fe14b937a62a9e77eb22ef41c51065e81e4dab9411d1f8bac2c0e6d34990
pdf-font-stream PDF embedded font (sfnt) at offset 0x165D3 16096 bytes