Malicious PDF — malware analysis report

Static analysis result for SHA-256 ec4e041afcdab6bc…

MALICIOUS

PDF

45.1 KB Created: 2020-08-18 17:07:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 2b5bee57c39a582e4fb0cf4be4c6a9f3 SHA-1: 7796dc99ad3be207d7ffc3ccd6adb776a4639940 SHA-256: ec4e041afcdab6bcda2ae4f2ade1db5bffef1c67ce7077904caf8177a4a21297
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1059.001 PowerShell T1204.002 Malicious Link

The PDF contains a malicious redirector link disguised as a 'happy birthday song with name app' lure. The ML classifier strongly indicated maliciousness, and the PDF was flagged for containing a mass external PDF link farm, with one of the links pointing to a known malicious redirector. The document body, though heavily obfuscated, contains the same lure text and URL as the malicious redirector. The primary attack vector appears to be social engineering via a deceptive link.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • 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.
  • 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://ttraff.ru/pify?keyword=happy+birthday+song+with+name+app
    • http://files.sewoldsewnew.com/uploads/1/3/1/3/131380971/a3c6f1a923addd9.pdf
    • https://cdn.shopify.com/s/files/1/0428/4229/2390/files/zefapal.pdf
    • https://cdn.shopify.com/s/files/1/0431/2550/6208/files/du_ba_sociology_syllabus.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/siwizobudavegi.pdf
    • https://cdn.shopify.com/s/files/1/0437/5399/6442/files/teoria_do_caos_e_a_abordagem_centrada_na_pessoa.pdf
    • https://cdn.shopify.com/s/files/1/0429/8063/8879/files/fetal_heart_doppler_app_for_android.pdf
    • https://cdn.shopify.com/s/files/1/0432/7319/1588/files/awards_and_honours_2020_19_download.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/27392185694.pdf
    • https://cdn.shopify.com/s/files/1/0433/4888/5662/files/35586316479.pdf
    • https://cdn.shopify.com/s/files/1/0431/3012/6496/files/fapalekegu.pdf
    • https://cdn.shopify.com/s/files/1/0430/4257/0401/files/nadipubewi.pdf
    • https://cdn.shopify.com/s/files/1/0429/8076/9951/files/8208964901.pdf
    • https://cdn.shopify.com/s/files/1/0438/1668/1629/files/ayyappa_swamy_bajana_songs_telugu.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/

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000645c.bin
fa32e2d63f1eb514530e250d76b48acb3080988fd4b613c8c1cdfcb4dada7ac7
pdf-font-stream PDF embedded font (sfnt) at offset 0x645C 5424 bytes
font_01_sfnt_off000076a5.bin
260d6fa370c8d04447bb3d52c92553a45089e66a13974094382d7fe16a0647c4
pdf-font-stream PDF embedded font (sfnt) at offset 0x76A5 10272 bytes
font_02_sfnt_off000099bb.bin
1158d95dac44631f497756703988ba3645251422e7ff0015d3fca430225e7c3e
pdf-font-stream PDF embedded font (sfnt) at offset 0x99BB 4324 bytes