Malicious PDF — malware analysis report

Static analysis result for SHA-256 ce770e288c27b1a0…

MALICIOUS

PDF

80.8 KB Created: 2021-03-10 23:48:13 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: 21d472306508db973d1bde200469486b SHA-1: 141e2ee9b2585d74b7303293bdcfc0e1b8413066 SHA-256: ce770e288c27b1a059f906d5c7b8557defd466a68818cc5f0a579eb2dddda933
244 Risk Score

Malware Insights

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

The PDF contains numerous external links, with one identified as a malicious redirector. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, a tool sometimes used to create malicious PDFs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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
  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://dafemum.ru/wb?keyword=luna%20julie%20anne%20peters%20quotes In PDF document text
    • https://static.s123-cdn-static.com/uploads/4425487/normal_5fc692d5f2a6f.pdfIn PDF document text
    • https://cdn.sqhk.co/zezinojox/jeZUCs7/spiral_perm_wrap.pdfIn PDF document text
    • https://cdn.sqhk.co/joxomawezu/ZmUW5b9/end_of_basketball_game_buzzer_sound_effect.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4455196/normal_60358846b51fb.pdfIn PDF document text
    • https://cdn.sqhk.co/vawapisoxe/hajfhac/autobrush_dentist_reviews.pdfIn PDF document text
    • https://cdn.sqhk.co/zebenane/cBWji49/wijeke.pdfIn PDF document text
    • https://cdn.sqhk.co/wodaximewule/IicWAhc/word_farm_cross_app.pdfIn PDF document text
    • https://cdn.sqhk.co/zenekukera/fihhVhd/57910116751.pdfIn PDF document text
    • https://cdn.sqhk.co/puroneruk/apKhaJo/injustice_gods_among_us_characters_skins.pdfIn PDF document text
    • https://cdn.sqhk.co/faruzikako/1bpxhhe/mentos_tv_ad_video.pdfIn PDF document text
    • https://cdn.sqhk.co/zixagiko/dijFKTj/flights_to_las_vegas_from_dallas_texas.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://441768bb-9839-4df4-8f78-dd1233b527f6.filesusr.com/ugd/7e6080_ccc0f0e6fbc14b45a6ca1de77e7cdf8e.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/29909d03-625a-4746-b36f-bec4f9067512/40784749418.pdfIn PDF document text
    • https://bb491b24-4c81-4ccc-8daa-bf1baeb171c2.filesusr.com/ugd/93c935_1e7073fc14994bf582d6803c7a44f384.pdf?index=trueIn PDF document text
    • https://efe523a3-d756-4f55-ba91-412f3a718e00.filesusr.com/ugd/236571_3e0a6ea097274a788ff2465bcfcbe7b2.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/a679ea6c-4403-4dbc-a5c7-d8f8910990f1/betagivote.pdfIn PDF document text
    • https://32b33340-d9da-4ef7-b3bd-a0ac5134eb71.filesusr.com/ugd/adfa6f_e25c06722463455f833b65b629733d73.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/4a0315b3-da74-473e-b806-e34fa43cd768/suzuvuzozesisilobib.pdfIn PDF document text
    • https://e0271a52-a7af-48e9-8a99-924ce320ec62.filesusr.com/ugd/be5703_c8cf782666e44d86adfa7cfa7ac6f450.pdf?index=trueIn PDF document text
    • https://010f2e21-25ca-4560-806d-08cbbb7c7db1.filesusr.com/ugd/74a852_8b00763209bb415bb837c6f86a6f2d02.pdf?index=trueIn 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_off00010044.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10044 4956 bytes
SHA-256: 67ed7776ee1ce234da20cda8af0f45a0654b3b61f4d1c4dd103920ea906a3eea
font_01_sfnt_off00011137.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11137 10764 bytes
SHA-256: 9bf66fb91cde0dcdf1fc490402776a9775d5f279325e239e3f5d4a8244634200