Malicious PDF — malware analysis report

Static analysis result for SHA-256 7f137cd7c860a629…

MALICIOUS

PDF

51.4 KB Created: 2020-08-13 21:51:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e0c89dba6ea907ec89bd53adde18d0e0 SHA-1: 6c2ae055d5f926569942427b8452f9c1654c4209 SHA-256: 7f137cd7c860a629d8bac9360ddb32fbf89ed806ca6a20d066037f108cf066f8
154 Risk Score

Malware Insights

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

The PDF contains a malicious redirector link disguised as an 'acceptance letter format for college' to lure victims. It also features a large number of external PDF links, many hosted on Shopify, likely for SEO poisoning or to obscure the malicious redirector. The ML classifier strongly indicated maliciousness.

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=acceptance+letter+format+for+college
    • http://zudobidi.vfw4809norfolk.org/uploads/1/3/0/8/130814328/4b465bd5.pdf
    • http://files.gryffehigh.com/uploads/1/3/1/4/131453429/63ff83bb0b28.pdf
    • http://files.ntfbstophunger.org/uploads/1/3/1/4/131438629/b7a8ab1b.pdf
    • http://files.mytotalnutrition.com/uploads/1/3/0/7/130775286/losatusimetegusebow.pdf
    • https://cdn.shopify.com/s/files/1/0431/3631/9645/files/lofifubisav.pdf
    • https://cdn.shopify.com/s/files/1/0431/8828/9694/files/sozuweva.pdf
    • https://cdn.shopify.com/s/files/1/0433/7418/2563/files/sezapigajodutefozarewix.pdf
    • https://cdn.shopify.com/s/files/1/0432/1342/2753/files/12782397976.pdf
    • https://cdn.shopify.com/s/files/1/0434/0511/5544/files/learning_python_beginner.pdf
    • https://cdn.shopify.com/s/files/1/0430/9565/4554/files/zekozebefoviraze.pdf
    • https://cdn.shopify.com/s/files/1/0430/9381/9541/files/38165415412.pdf
    • https://cdn.shopify.com/s/files/1/0433/5396/4712/files/dinosepimupezutizaxeb.pdf
    • https://cdn.shopify.com/s/files/1/0430/8746/2551/files/besijekirewot.pdf
    • https://cdn.shopify.com/s/files/1/0436/7666/3961/files/gakoj.pdf
    • https://cdn.shopify.com/s/files/1/0431/2186/8960/files/berlin_u_bahn_map_2020.pdf
    • https://cdn.shopify.com/s/files/1/0432/1044/0862/files/50730870933.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_off00007dbd.bin
ba19ee4e8ad42a5d6dc4b470371b0793a7511617ea715c550e669c090040182b
pdf-font-stream PDF embedded font (sfnt) at offset 0x7DBD 4884 bytes
font_01_sfnt_off00008e32.bin
b88bbea1a8c5c8a24768a3206bd2681562b94533fa5efadd51ebd5cd92023731
pdf-font-stream PDF embedded font (sfnt) at offset 0x8E32 10676 bytes
font_02_sfnt_off0000b2a1.bin
a542ec26cea93e049a2e27cd59b1347dd9bbdea13775fd7b822b3c2b3136116f
pdf-font-stream PDF embedded font (sfnt) at offset 0xB2A1 4324 bytes